Jumat, 13 April 2018

What is an Escherchia coli infection?





Jual Culture Escherchia coli
Telp. 087731375234

Escherchia coli is the name of a germ, or bacterium, that lives in the digestive tracts camera.gif of humans and animals.There are many types of E. coli, and most of them are harmless. But some can cause bloody diarrhea. Some strains of E. coli bacteria may also cause severe anemia or kidney failure, which can lead to death.Other strains of E. coli can cause urinary tract infections or other infections.What causes an E. coli intestinal infection?.You get an E. coli infection by coming into contact with the feces, or stool, of humans or animals. This can happen when you drink water or eat food that has been contaminated by feces.
Escherchia coli can get into meat during processing. If the infected meat is not cooked to 160°F (71°C), the bacteria can survive and infect you when you eat the meat. This is the most common way people in the United States become infected with E. coli. Any food that has been in contact with raw meat can also become infected.Other foods that can be infected with E. coli include:Raw milk or dairy products. Bacteria can spread from a cow's udders to its milk. Check the labels on dairy products to make sure they contain the word "pasteurized." This means the food has been heated to destroy bacteria.Raw fruits and vegetables, such as lettuce, alfalfa sprouts, or unpasteurized apple cider or other unpasteurized juices that have come in contact with infected animal feces.
Human or animal feces infected with E. coli sometimes get into lakes, pools, and water supplies. People can become infected when a contaminated city or town water supply has not been properly treated with chlorine or when people accidentally swallow contaminated water while swimming in a lake, pool, or irrigation canal. The bacteria can also spread from one person to another, usually when an infected person does not wash his or her hands well after a bowel movement. E. coli can spread from an infected person's hands to other people or to objects.

Aspergillus oryzae And Aspergillus sojae in Industry of Kecap






Jual Starter  Aspergillus oryzae, Aspergillus sojae 
Telp. 087731375234


 Aspergillus oryzae and Aspergillus sojae strains generally are used for shoyu and saoce soyabean (kecap) production have focused on comparing these two fungal species and improving their enzyme-producing abilities. A study of the enzymatic differences between 11 strains of Aspergillus oryzae and 20 strains of Aspergillus sojae showed that the activities of neutral, acid, and alkaline proteases, xylanase, pectin lyase, phosphatase, and aminopeptidase were not significantly different. However, acid carboxy peptidase activity and α-amylase activity were higher from A. oryzae when compared with A. sojae strains, while endopolygalacturonidase activity was much higher from A. sojae than from A. oryzae . The ratios between α-amylase activity and endopoly galacturonidase activity of 0.5–2 for A. sojae and 20–2000 for A. oryzae were suggested as a differentiation criterion for the species (Terada et al., 1980). Hayashi et al. (1981) compared the performance of these two fungi in shoyu production. They found that the activities of protease, acetic carboxypeptidase, and α-amylase were lower and those of endopolyglueuronidase and glutaminase were higher in koji made with A. sojae.
In the moromi stage, the proportions of NH3 nitrogen (N), glutamic acid N, and total Ν were higher, and viscosity and heat residue were lower with A. sojae. The resulting concentrations of citric and succinic acids in the shoyu were significantly higher (p < 0.001) with A. sojae than with A. oryzae. Ishihara et al. (1996) compared the volatile components in commercial koikuchi shoyus from different factories using either A. oryzae or A. sojae and found that the concentrations of 1- and 2-propanol, furfuryl and benzyl alcohols, ethyl-benzoate, and lactate, acetate, pyrazines, carbonyl compounds such as ethanal, maltol, and phenyl acetaldehyde, phenol, and others, were higher in the shoyu from factories using the latter fungus, but concentrations of 2-methyl- and 3-methyl − 1-butanol, 2-phenyl ethanol, 2-methyl- and 3-methyl-butanoic acid, 3-methylthio − 1-propanol, HEMF, 4-ethyl guaiacol, 4-ethyl phenol, and others were greater in shoyu from factories using the former fungus. These results have prompted factory managements to use A. sojae for koji production.
Using an unusual system, Yasui et al. (1982) tested a range of koji fungal strains for glutaminase production and found that, when a strain showing 16% higher glutaminase activity than its parent strain was compared with its parent in the production of shoyu, the final glutamic acid concentration was 10% higher. In the early 1950s, A. sojae KS was irradiated with X-rays by Iguchi to produce strain X-816 of A. sojae (Sekine et al., 1970). Sekine et al. (1970) obtained seven strains with superior alkaline phosphatase activity (130–190%) and highly active protease, peptidase, cellulase, and amylase activities that were better at decomposing soybean protein. Yokoyama and Kadowaki (1983) UV-irradiated A. sojae strain Η and obtained mutant strains with total protease activities 2.5 times that in wheat bran and soy sauce kojis. The mutant strains were diploidized and combined with natural mutants from Μ strains, and strains TH and D-15 were produced that possessed higher total protease activities than the Μ strains, and grew well. However, UV irradiation may stimulate the production of toxic elements in otherwise safe fungi. Kalayanamitr et al. (1987) UV-irradiated A. flavus var. columnaris Raper and Fennel (ATCC44310) to obtain mutant strains with high protease and amylase activities, and light-colored conidia. Some selected mutant strains were found to be acutely toxic to weanling rats, even though they were negative for aflatoxin production. The investigators suggested that the toxic compound could be one of four substances: maltorhyzine, aspergillic acid, kojic acid, or cycoopiazonic acid.
Furuya et al. (1983) fused, with an efficiency of 1%, protoplasts derived from two strains of A. oryzae, one with a high growth rate and the other producing high levels of protease. Two strains derived from successful fusions showed high stability, fast growth, and abundant sporulation and produced 2.3 times more protease than the parent fast-growth strain.
The growth and development of microorganisms on defatted soybean and ground wheat koji prepared with A. sojae were studied by electron microscopy by Kitahara et al. (1980). Growth of the mold on the surface of the soybean was rapid up to 24 h, at which point formation of sporing bodies began, and spores were released within 40 h. However, very little fungal growth was seen on the wheat surface, but yeasts were seen growing on the wheat. Growth of Micrococcus species became noticeable after 16 h, as did multiplication of lactobacilli. These observations on the growth of the koji mold are at odds with the observation that 10–20% of the dry matter in koji is lost in the koji stage (Takeuchi et al., 1968) and the observations below on the significant consumption of carbohydrate during the koji stage. I suggest that significant penetration of the wheat endosperm should have been seen.
During koji production, carbohydrate is consumed by the fungus, thus leaving less carbohydrate available to provide flavor compounds for the final shoyu produced (Furuya et al., 1985). This carbohydrate consumption is positively correlated with α-amylase activity in koji culture. To overcome the depletion of carbohydrate before the moromi stage, Furuya et al. (1985) derived mutants that utilized 10–50% less carbohydrate during preparation of koji than the parent strain, with about 1/3, 1/20, and 1/150 of the α-amylase activity of the parent strain of A. oryzae. Significantly increased amounts of carbohydrate-derived compounds were found in the resulting shoyu made with these mutants.
Enhanced glutaminase activity in koji is desirable to increase glutamic acid production in soy sauce, and reduced conidial production in the koji reduces contamination of the air with floating conidia (Ueki et al., 1994a). A mixed tane koji of two koji fungi, A. oryzae strains K2 and HG, increased glutaminase activity of the mixture to 11.3 units · g− 1 dry koji, which was higher than the 4.7 or 4.4 units · g− 1 dry koji produced by the K2 strain or HG strain, respectively, and conidia production was reduced tenfold (Ueki et al., 1994a). The mixed tane koji was used in the manufacture of soy sauce, and the resulting mixed koji made with 3.6 tons of defatted soybean and of wheat grain showed high glutaminase activity (5.5 units · g− 1 dry weight koji) when compared to strain K2 alone (1.8 units · g− 1 dry weight koji). In addition, the number of conidia in the mixed culture was 2.5 × 107 g− 1 dry koji, which was lower than 1.3 × 108 g− 1dry koji produced by strain K2 alone. The glutamic acid content of the raw soy sauce was 1.25 times higher than the glutamic acid level found in normal soy sauce (Ueki et al., 1994b).
Kim and Cho (1975) investigated soy sauce production in Korea using a soy–wheat koji prepared with A. sojae, using natto, a soy bean product prepared with Bacillus natto, and using a mixture of the two in varying proportions. The natto–brine mixture had protease activity twice as high as the koji alone, and this was reflected in the protease activities found in mixtures of the natto and koji. On comparing the organoleptic qualities of soy sauces fermented for 3 months, the koji:natto at a ratio of 6:4 had the best flavor, followed by koji alone.

http://www.sciencedirect.com


Rabu, 11 April 2018

Bacillus polymixa






Jual Culture Bacillus polymyxa
Telp. 0877.3137.5234



Paenibacillus polymyxa (Bacillus polymixa) is an endospore-forming bacterium that is non-pathogenic and found in environments such as plant roots in soil and marine sediment. P. polymyxa is a Gram-positive, rod-shaped bacterium, that is also motile. It achieves motion via peritrichous flagella. The wide range of capabilities of this bacterium are to fix nitrogen, produce hormones that promote plant growth, produce hydrolytic enzymes, and to produce antibiotics against harmful plant and human microorganisms. It can also help plants in absorption of phosphorus and enhance soil porosity. This microbe has a role in ecosystem function and potential role in industrial processes.
In agricultural ecosystems P. polymyxa can promote plant growth through three mechanisms. The first mechanism is production of hormones like cytokinins, auxins, ethylene and gibberellins. These compounds increase root expansion and plant growth. The second mechanism is production of antibiotics and promoting immunity of rhizosphere. Heulin et al. (1994) observed that antagonistic activity of P. polymyxa decreased the activity of two plant pathogenic fungis (Gaeumannomyces graminis var. tritici and Fusarium oxysporum). The third mechanism is the bacterium's nitrogen fixing ability that can produce a form of nitrogen (ammonia NH3) that is usable by plants from atmospheric N2. In addition, soil fluctuation and porosity is improved due to organic compounds released from P. polymyxa into the soil.
The wide ranges of applications of P. polymyxa in industry are due to secondary metabolites produced by this bacterium. The antimicrobial compounds are effective against a wide range of Gram-positive and Gram-negative bacterial species therefore the bacteria can be used in biopreservation of food and medical applications. Metabolites such as polymyxin E1 and a lantibiotic also decrease the colonization of pathogens in poultry and shrimp larvae. The other area of application of metabolites produced by the bacterium is bioflocculation caused by metabolites such as 2,3-butanediol (BDL). The bacterium has also been used for separation of hematite, pyrite and chalcopyrite [7]. Waste and tap water treatment and fermentation are other areas of industrial application of P. polymyxa.
Paenibacillus was originally classified under the genus Bacillus until it became its own genus in 1993 [8]. This distinction was made using comparative analysis of the 16S rRNA gene sequence of three different bacilli which showed enough phylogenetic distance from Bacillus subtilis to warrant a new genus [8]. Paenibacillus (paene + Bacillus) means almost Bacillus in Latin. P. polymyxa SC2 and P. polymyxa E681 have had their entire genomes sequenced. The complete genome of P. polymyxa SC2 is composed of a 5.7 Mb circular chromosome with about 5,400 coding genes and a 510 kb plasmid with about 649 coding genes . The complete genome of P. polymyxa E681 is composed of a 5.3 Mb circular chromosome with about 4,800 genes and no plasmids [10]. P. polymyxa SC2 and E681 have 54.58% and 45.80% G+C content respectively. It was found that P. polymyxa has several genes involved in antibiotic biosynthesis encoded in the chromosome.
P. polymyxa is an anaerobic nitrogen-fixing Gram-positive bacterium that is rod-shaped, 0.6 by 3.0 μm in size, and produces pale colonies on agar. For reproduction it differentiates into ellipsoidal spores which distinctly swell the mother cell. The endospore can germinate when conditions are more suitable. Spore germination of P. polymyxa can be influenced by many factors including heat activation and nutrients such as fructose plus L-alanine . Organic acids can also affect the heat resistance of spores. When P. polymyxa isn’t in an endospore form, it has peritrichous flagella that aid in motility and swarming.
P. polymyxa is a chemoorganoheterotroph that can fix atmospheric nitrogen and is a facultative anaerobe. As a facultative anaerobe, it can perform aerobic respiration in the presence of oxygen or switch to fermentation when oxygen levels are low. It can use a variety of organic carbon sources such as glucose, sucrose, maltose, and arabinose and can produce a number of metabolites such as acetoin, lactate, and ethanol [13]. It is also a mesophile that grows optimally around 30°C and the optimum pH is around 4-7. P. polymyxa also has the ability to produce H2 gas as a byproduct during a fermentative process that is affected by both pH and temperature. This fermentative process, called acetogenesis, yields acetate, hydrogen, and CO2, which can be used as precursors by methanogens to produce methane. P. polymyxa has the unique capability of synthesizing antibiotics/antifungal compounds. Three of these compounds include polymxin, paenibacillin, and fusaricidin.
P. polymyxa is found in variety of environments such as soils, the rhizosphere of plants, and marine sediments. In the rhizosphere, P. polymyxa has pathogenic traits against deleterious microorganisms (mainly fungi). It also has a symbiotic relationship with plants by invading their roots and forming biofilms. Production of hormones and nitrogen fixation are other beneficial activities of the bacterium in soil and rhizosphere. P. polymyxa also has antagonistic activity against Vibrio species and many other human and animal pathogenic microorganisms. Therefore, it has been used in production of commercial antimicrobials. Polymyxin B, one of the antibiotics produced by P. polymyxa, is one of the compounds found in the common antibacterial topical cream Neosporin.This bacterium produces secondary metabolites that have wide applications in agricultural ecosystems, biopreservation in food and medicine industry, bioflocculation in waste water and mineral processing.
P. polymyxa has a unique capability of protecting tomato seedlings from bacterial wilt [18]. Bacterial wilt is caused by Ralstonia solanacearum, a bacterium found in the soil that infects plants [19]. R. solanacearum invades the plant through the roots and colonizes in the vascular bundles in the xylem vessels. As it grows and multiplies, it blocks the transportation of water and nutrients. P. polymyxa can prevent this bacterial wilt by colonizing and forming a biofilm around the roots of the tomato seedling, preventing the entrance of R. solanacearum.
P. polymyxa also has potential uses in bioremediation. It surrounds itself with a compound called exopolysaccharide (or extracellular polymeric substance), which is important for biofilm formation and adhering to plant roots and soil particles. This exopolysaccharide can be used as an inexpensive and easily cultivable compound to remove cadmium (Cd2+) from aqueous solutions [20]. This is achieved by the absorption of cadmium in the aqueous solution into the exopolysaccharide of P. polymyxa. Additionally, P. polymyxa can be used in the bioremediation removal of reactive blue 4 (RB4), a dye used on fabrics that is not readily removed from water by wastewater treatment processes [14]. Watanapokasin et al. (2008) observed decolorization with dye removal by P. polymyxa along with a hydrogen byproduct that could be used as a potential energy source. This decolorization occurred via a process called acidogenesis.

https://microbewiki.kenyon.edu

The Usage of Aspergillus oryzae








Jual Culture Aspergillus oryzae Dan Starter Serbuk Aspergillus oryzae
Telp. 087731375234


Aspergillus oryzae is a filamentous fungus, or mold, that is used in East Asian (particularly Japanese and Chinese) food production, such as in soybean fermentation. A. oryzae is utilized in solid-state cultivation (SSC), which is a form of fermentation in a solid rather than a liquid state. This fungi is essential to the fermentation processes because of its ability to secrete large amounts of various degrading enzymes, which allows it to decompose the proteins of various starches into sugars and amino acids. This fungi is characterized by a round vesicle with extending conodial chains, which appear as white and fluffy strands on the substrate that the fungi inhabits.
The full genome of A. oryzae  contains eight chromosomes and the mitochondrion (which is circular, rather than linear) and is estimated to be 37.6Mb, or 37,878,829 bp, in size. It contains 12,074 genes, and is 7-9Mb longer (or 25-30% larger) than other members of the Aspergillus genus, namely the species A. nidulans and A. fumigates. A. oryzae's linear genome is made up of 48.25% GC-content, or guanine-cytosine content, which is an indicator of a higher melting point. There are 12,084 ORFs (open reading frames) within the genome, which may potentially code for essential proteins or peptides. Coding regions account for 44.02% of the genome, whereas there are only 7.48% intronic regions. Additionally, the A. oryzae genome contains 270 tRNA genes, and only 3 rRNA genes.
When comparing the three Aspergillus species, it was found that in A. oryzae a combination of syntenic blocks derived from a singular ancestral region and blocks specific to A. oryzae arranged mosaically comprised the full genome. The A. oryzae-specific sequence codes for metabolite synthesis and specific gene expansion for secreting hydrolytic enzymes when used in SSF, or solid-state fermentation, which makes it such an effective microbe in fermentation processes.
Close relatives of Aspergillusoryzae, Aspergillusflavus and Aspergillusniger contain syntenic genes from a singular ancestor, such as a set of twenty-five proteins which code for a pathway for the poisonous aflatoxin. Yet unlike in relatives Aspergillusflavus and Aspergillusniger, these genes fail to be expressed in Aspergillusoryzae, indicating that they were inactivated during its specific evolution.[5] Because A. oryzae has been domesticated, it is possible that gene expansion is due to horizontal gene transfer, as is seen in A. oryzae-specific genes, which use clonal lines to transfer chromosomes.
A. oryzae, along with most other members of the Aspergillus family, has a hyphae that is hyaline and septate, and conidiophore, which ends at a round-shaped vesicle. From the vesicle extend long filaments called a conodial chain, which appear as long fluffy strands on the surface of the substrate. The spore-bearing cells, or asci, are produced within the ascocarp, or the fruiting body. The primary enzyme secreted by the filamentous fungi is called amylase, which lends a sweet taste to the food it is fermented into. This enzyme is most efficient at a temperature of 35-40 degrees Celsius. Most other enzymes found in A. oryzae grow at a temperature of around 30-35 degrees Celsius.
Members of the Aspergillus genus are distinct from other microbes due to the fact that they utilize both a primary and secondary metabolic system. The functionality of the Aspergillus metabolism depends on its carboxylic acids, which break down into fatty acid chains that are composed of a unique set of fatty acid synthase complexes. These chains aid in the development of the Aspergillus cell membrane and the enzyme storage vesicles. The primary metabolism of A. oryzae receives its energy through contact with energy sources (e.g. grains or starches). Once it makes contact with an energy source, it secretes enzymes that degrade the proteins and peptide bonds within the starch and convert them into amino acids and sugars for consumption.
The secondary metabolism utilizes acidic compounds to suppress metabolic pathways, which allows  A. oryzae to produce secondary metabolites. These metabolites grant A. oryzae the ability to modify themselves according to their current environment--they are able to increase or decrease their fitness to allow optimum metabolic efficiency. This ensures that fungi within the Aspergillus genus are able to adapt to a wide range of environments. Most of what is currently known about secondary metabolites is comprised of the polyketide molecules generated from the acidic compounds within the secondary metabolism.
It was previously thought that A. oryzae could only reproduce asexually through mitosis by dispersing spores using conidiophores. Yet, it was recently found to contain an alpha mating-type gene within its genome which implicates a heterosexual mating process. Despite this, asexual reproduction is favored in all conditions, and rarely will sexual reproduction be utilized. A. oryzae grows under warm temperatures and moist environments, as most fungi and mold do. As it matures, the filaments grow longer into a white, fluffy texture.
A. oryzae tend to prefer environments that are rich in oxygen, as they are molds that inhabit the surface of various substrates that provide beneficial nutrients to them. They also prefer environments between 30 and 40 degrees Celsius that have adequate moisture for the spores to cultivate and propagate. A. oryzae are a domesticated species and are most commonly found in northern regions, specifically in East Asia, but can be found anywhere. The Aspergillus genus is extremely common, although A.oryzae specifically is more rare due to its domestication for use in fermentation in the food industry.
A. oryzae is considered to be a pathogenic microbe because of the fungi's contamination of carbon-rich and starchy foods such as beans, rice, or bread as well as various trees and plants. Also, the Aspergillus genus is characterized by its mycotoxins, primarily kojic acid, produced by the secondary metabolism of A. oryzae and close relatives. A. oryzae can also produce toxins such as maltoryzine, cyclopiazonic acid, and b-nitropropionic acid due to its close relationship to A. flavus.[3]
Despite this, A. oryzae has been determined to be relatively safe for use in food processing because of its domestication and evolution from wild-type relatives A. flavus and A.niger, which led to an inactivation the proteins that code for its toxin pathway. The production of kojic acid in members of the Aspergillus genus was found to be strain-specific and and environmentally-based. For A. oryzaespecifically, the release of the mycotoxinkojic acid could be triggered by an environment of extended fermentation, but as long as adequate precautions are taken in industrial processes, the fungi is safe.[9] Other than this, the greatest risk from A. oryzae is airborne spores that could be inhaled in large amounts by industrial workers.
As A. oryzae is a fungus native to humid East Asian regions, it is a microorganism that is primarily used in Japanese and Chinese food production. [6] A. oryzae is utilized in solid-substrate cultivation (or SSF) which is a fermentation process used to make various different kinds of foods, from soy sauce to sake and vinegar due to its ability to secrete a multitude of useful enzymes. A. oryzae is said to have the greatest potential in efficient production of enzymes of those within the Aspergillus genus, and is therefore taken advantage of in the fields of genetic engineering and biotechnology to create industrial enzymes for even more profitable manufacturing.
In solid-substrate cultivation, A. oryzae is sprinkled over rice, barley, or soybeans and fermented at a specific temperature ideal for fungus growth. The A. oryzae is sprinkled on the grain at a temperature under 45 degrees Celsius, and the fungus (called tanekoji or "seed koji" by the Japanese) grows on the steamed rice, which then raises in temperature and moisture level to allow the fungus to propagate. The enzymes it secretes break down the starches and proteins within the grains and convert it into amino acids and sugars. A grain with properly-grown fungi mycelium is characterized by fluffy, white filaments covering the outside.
The production of koji, the product of the filamentous fungus A. oryzae and the chosen grain, and the techniques to cultivate it are kept a secret by each koji company.
References

[1] Machida, M., Yamada O., and Gomi K. "Genomics of Aspergillusoryzae: Learning from the History of Koji Mold and Exploration of Its Future." Oxford Journals: DNA Research. Volume 15(4). p. 173-183
[2] Machida M., Asai K., Sano M., Tanaka T., Kumagai T., Terai G., Kusumoto K., Arima T., Akita O., Kashiwagi Y., Abe K., Gomi K., Horiuchi H., Kitamoto K., Kobayashi T., Takeuchi M., Denning D. W., Galagan J. E., Nierman W. C., Yu J., Archer D. B., Bennett J. W., Bhatnagar D., Cleveland T. E., Fedorova N. D., Gotoh O., Horikawa H., Hosoyama A., Ichinomiya M., Igarashi R., Iwashita K., Juvvadi P. R., Kato M., Kato Y., Kin T., Kokubun A., Maeda H., Maeyama N., Maruyama J., Nagasaki H., Nakajima T., Oda K., Okada K., Paulsen I., Sakamoto K., Sawano T., Takahashi M., Takase K., Terabayashi Y., Wortman J. R., Yamada O., Yamagata Y., Anazawa H., Hata Y., Koide Y., Komori T., Koyama Y., Minetoki T., Suharnan S., Tanaka A., Isono K., Kuhara S., Ogasawara N., Kikuchi H. Genome sequencing and analysis of Aspergillusoryzae. Nature 2005.Volume 438.p.1157-1161.
[3] "Aspergillusoryzae Final Risk Assessment." Biotechnology Program under the Toxic Substances Control Act (TSCA). United States Environmental Control Agency. February 1997.
[4] Rokas, A. "The effect of domestication on the fungal proteome." Trends Genetics 2009.Volume 25(2).p.60-63.
[5] Goffeau, A. "Genomics: Multiple moulds". Nature 2005.Volume 438 (7071). p. 1092-93.
[6] Fujita, Chieko. "Koji, an Aspergillus." The Tokyo Foundation. Dec 16, 2008. Accessed April 28 2015.
[7] "Aspergillusoryzae RIB40 (= NBRC 100959)." National Institute of Technology and Evaluation.DOGAN. January 2014. Accessed April 28 2015.
[8] Brown D., Adams T., and Keller N. "Aspergillus has distinct fatty acid synthases for primary and secondary metabolism." Proceedings of the National Academy of Sciences 93, no. 25 (1996): 14873-14877.
[9] Blumenthal, C. "Production of toxic metabolites in Aspergillusniger, Aspergillusoryzae, and Trichodermareesei: justification of mycotoxin testing in food grade enzyme preparations derived from the three fungi." RegulToxicolPharmacol 2004. Volume 39(2).p.214-28.

Minggu, 25 Maret 2018

Mengolah Singkong Menjadi Glukosa







Jual Ezim alfa amylase, gluco amylase
087731375234 

Singkong telah banyak diolah menjadi berbagai macam produk diantaranya adalah; tapioka, mocaf, nata de cassava, bioetanol, gula cair (glukosa), pakan ternak, aneka makanan camilan. Produksi singkong hampir tersebar di seluruh Indonesia. Potensi komoditas singkong sebagai bahan baku industri harus terus dikembangkan. Penemuan teknologi proses mengolah singkong menjadi gula cair berupa glukosa merupakan peluang bisnis yang menjanjikan, serta akan mengurangi ketergantungan gula impor. Gula merupakan salah satu kebutuhan mendasar untuk memenuhi kebutuhan rumah tangga dan industri yang terus berkembang. Permintaan gula semakin meningkat dari tahun ke tahun, sedangkan produksi gula yang umumnya didominasi gula tebu, produktifitasnya semakin menurun. Sehingga perlu dicarikan alternatif gula subtitusi yang ketersediaan bahan baku nya melimpah dan efesien.
Glukosa, suatu gula monosakarida, adalah salah satu karbohidrat terpenting yang digunakan sebagai sumber tenaga bagi hewan dan tumbuhan. Glukosa merupakan salah satu hasil utama fotosintesis dan awal bagi respirasi. Bentuk alami (D-glukosa) disebut jugadekstrosa, terutama pada industri pangan. Glukosa (C6H12O6, berat molekul 180.18) adalah heksosa—monosakarida yang mengandung enam atom karbon. Glukosa merupakan aldehida (mengandung gugus -CHO).
Secara umum, proses pembuatan gula cair  terdiri atas dua tahap yaitu: tahap likuifikasi dan sakarifikasi dengan menggunakan enzim. Likuifikasi merupakan pemecahan pati menjadi dekstrin dengan bantuan enzim alfa-amilase.Sedangkan sakarifikasi berupa penguraian dekstrin menjadi glukosa dengan enzim amiloglukosidase.Pada tahap likuifikasi, tapioka dicampur air dengan perbandingantiga liter air 1 Kg tapioka, sambil diaduk rata tambahkan1 ml enzim alfa-amilase per kg pati tapioka, panaskan pada suhu 95-105 oC. Tingkat keasaman larutan juga dipertahankan pada pH 6,0-6,5.
Proses selanjutnya adalah sakarifikasi yang berlangsung selama 76 jam yaitu dengan mendinginkan media larutan hingga suhu 60oC, kemudian tambahkan 1 ml enzim amiloglukosidase per kg pati. Arang aktif mampu mengikat, menggumpalkan, dan mengendapkan kotoran-kotoran yang terdapat dalam gula cair.Selain itu arang aktif berfungsi menghentikan aktivitas enzim.Setelah itu lakukan penyaringan untuk memisahkan gula cair dengan karbon aktif dan endapan kotoran. Penyaringan bertujuan menghasilkan gula cair dengan tingkat kejernihan 93%.Bila belum tercapai, ulangi kembali penyaringan.
Tahap terakhir adalah evaporasi.Produsen memasukkan gula cair yang telah melewati tabung penukar ion itu ke dalam evaporator untuk meningkatkan kemurnian gula. Proses evaporasi berlangsung pada suhu 50-60oC. Indikasi evaporasi selesai ketika gula cair berhenti menetes dari pipa evaporator. Dengan pemurnian itu kadar kemanisan gula cair meningkat, semula 30-36o briks menjadi 60-80o briks.
Tahapan Proses Membuat Gula Cair Bahan Baku Singkong
1.      Larutkan tepung tapioka dalam air dengan perbandingan 1 : 3.
2.      Panaskan pada suhu 95-105oC dan tambahkan 0,8 ml enzim alfa-amilase per kg pati sembari diaduk rata.
3.      Setelah mendidih, turunkansuhu larutan hingga bersuhu 60oC. Kemudian tambahkan 1 ml enzim amiloglukosidase per kg pati. Diamkan larutan selama 76 jam hingga menjadi cairan gula.
4.      Tambahkan 0,5-1% arang aktif per kg pati ke dalam gula cair untuk mengikat, menggumpalkan, dan mengendapkan pati, serta menghentikan aktivitas enzim.
5.      Lakukan penyaringan larutan untuk memisahkan gula cair dari karbon aktif dan kotoran sehingga tingkat kejernihan gula 93%. Bila belum tercapai, ulangi kembali pemucatan dan penyaringan.
6.      Alirkan gula cair melalui tabung berisi penukar ion untuk mengikat dan memisahkan ion-ion logam dan kotoran dalam gula cair. Tabung penukar ion terdiri atas 3 tabung masing-masing berisi resin kation, kation, dan campuran anion dan kation.
7.      Evaporasi gula ke dalam evaporator untuk meningkatkan kadar gula. Proses evaporasi berlangsung pada suhu 50-60oC.

 



Pseudomonas flourescens Dalam Dunia Pertanian






Jual Culture Pseudomonas flourescens
087731375234



Pseudomonas flourescens adalah mikroba dari gologan bakteri yang merupakan salah satu genus dari Famili Pseudomonadaceae. Pseudomonas flourescens yang memiliki karakteristik aerob (memanfaatkan oksigen sebagai penerima electron), namun sebagian spesies bersifat anaerobic yaitu menggunakan nitrat sebagai alternative penerima electron dalam respirasi. Bakteri ini berbentuk batang lurus atau lengkung, ukuran tiap sel bakteri 0,5 x 1-4μm. Ciri-cirinya yaitu menghasilkan pigmen fluorescent yang larut dalam air, yaitu pigmen hijau kuning disebut pyocyanin dan pyoverdin yang menyebar ke media dan fluorescent di bawah sinar ultraviolet.
Pyocyanin sadalah phenazine berwarna biru (Nonphotosynthetic Protobacteria). P. Fluorescens mengeluarkan pigmen hijau, merah hijau, merah jambu, dan kuning terutama pada medium yang kekurangan unsure besi. P. Fluorescens membentuk pigmen berpendar yang dikenal dengan nama fluorescein. Akan tetapi, sekarang lebih banyak digunakan istilah pyoverdin untuk menghilangkan kebingungan dengan fluorescein yang disintesisse cara kimia, yakni resorcinolphthalein. Pyoverdin terdiri atas peptide 5-8 asam amino dan kromofor turunan kuinolin yang memiliki berat molekul sekitar 1.000. Pyoverdin mempunyai kemampuan sebagai senyawa pengikat besi dan pengangkut besi. Termasuk ke dalam bakteri yang dapat ditemukan dimana saja (ubiquitous), seringkali ditemukan pada bagian tanaman (permukaan daun dan akar) dan sisa tanaman yang membusuk, tanah dan air. Dengan kemampuan untuk melindungi akar dari infeksipatogen tanah dengan cara mengkolonisasi permukaan akar, menghasilkan senyawa kimia seperti anti jamur dan antibiotic serta kompetisi dalam penyerapankation Fe.
Bakteri ini juga menghasilkan fitohormon dalam jumlah yang besar khususnya IAA untuk merangsang pertumbuhan dan pemanjangan batang pada tanaman. Adapun mekanisme pelarutan fosfat oleh bakteri pelarut fosfat diawali dari sekresi asam-asam organic diantaranya asam formiat, asetat, propionat, laktat, glikolat, glioksilat, fumarat, tartat, ketobutirat, suksinat dan sitrat, dengan meningkatnya asam-asam organic tersebut akan diikuti dengan penurunan nilai pH sehingga mengakibatkan terjadinya pelarutan P yang terikat oleh Ca. Beberapa hasil penelitian menyatakan bahwa Pseudomonas flourescens dapat mengendalikan : penyakit layu fusarium pada tanaman pisang, penyakit virus kuning pada tanaman cabai penyakit layu bakteri (Ralstonia solanacearum) pada tanaman kacang tanah. Istilah rizosfer pertama sekali diperkenalkan oleh Hiltner pada tahun 1904, yang didefenisikan tanah yang mengelilingi akar yang dapat mempengaruhi pertumbuhan mikroorganisme.
Karena Pseudomonas flourescens yang hidupdi daerah perakaran tanaman dapat berperan sebagai jasad renik pelarut fosfat, mengikat nitrogen dan menghasilkan zat pengatur tumbuh bagi tanaman sehingga dengan kemampuan tersebut Pseudomonas flourescens dapat dimanfaatkan sebagai pupuk biologis yang dapat menyediakan hara untuk pertumbuhan tanaman.

DaftarPustaka
Rao NSS. Mikroorganisme Tanah dan Pertumbuhan Tanaman. Jakarta: UI-Press. 1994
ArdianaKartika B.2012.  Teknik Eksplorasidan Pengembangan Bakteri Pseudomonas
flourescens. www.laboratoriumphpbanyumas.com/isiwebsite/AGENSIA HAYATI/eksplorasi Pseudomonas Flourescens.pdf. diakestanggal 26 Desember 2013 pukul 21.00
Supriadi., 2006. Analisis Resiko Agens Hayati Untuk Pengendalian Patogen Pada Tanaman. Dalam Jurnal Litbang Pertanian 25 (3), 2006.
Suryadi, Y., 2009. Efektifitas Pseudomonas flourescens Terhadap Layu Bakteri (Ralstonia solanacearum) Pada Tanaman Kacang Tanah. DalamJurnal HPT Tropika.ISSN 1411-7525. Vol. 9 No. 2 ; 174 – 180, September ,2009.


Saccharomyces cerevisiae





Jual Culture Saccharomyces cerevisiae
087731375234


Saccharomyces cerevisiae is a species of yeast. It is believed to have been originally isolated from the skin of grapes (one can see the yeast as a component of the thin white film on the skins of some dark-colored fruits such as plums; it exists among the waxes of the cuticle). It is one of the most intensively studied eukaryotic model organisms in molecular and cell biology, much like Escherichia coli as the model bacterium. It is the microorganism behind the most common type of fermentation. S. cerevisiae cells are round to ovoid, 5–10 μm in diameter. It reproduces by a division process known as budding.
Many proteins important in human biology were first discovered by studying their homologs in yeast; these proteins include cell cycle proteins, signaling proteins, and protein-processing enzymes. S. cerevisiae is currently the only yeast cell known to have Berkeley bodies present, which are involved in particular secretory pathways. Antibodies against S. cerevisiae are found in 60–70% of patients with Crohn's disease and 10–15% of patients with ulcerative colitis (and 8% of healthy controls).
"Saccharomyces" derives from Latinized Greek and means "sugar-mold" or "sugar-fungus", saccharo (σάκχαρις) being the combining form "sugar" and myces (μύκης, genitive μύκητος) being "fungus". Cerevisiae comes from Latin and means "of beer". Other names for the organism are:
In the 19th century, bread bakers obtained their yeast from beer brewers, and this led to sweet-fermented breads such as the Imperial "Kaisersemmel" roll,[4] which in general lacked the sourness created by the acidification typical of Lactobacillus. However, beer brewers slowly switched from top-fermenting (S. cerevisiae) to bottom-fermenting (S. pastorianus) yeast and this created a shortage of yeast for making bread, so the Vienna Process was developed in 1846.[5] While the innovation is often popularly credited for using steam in baking ovens, leading to a different crust characteristic, it is notable for including procedures for high milling of grains (see Vienna grits[6]), cracking them incrementally instead of mashing them with one pass; as well as better processes for growing and harvesting top-fermenting yeasts, known as press-yeast.
Refinements in microbiology following the work of Louis Pasteur led to more advanced methods of culturing pure strains. In 1879, Great Britain introduced specialized growing vats for the production of S. cerevisiae, and in the United States around the turn of the century centrifuges were used for concentrating the yeast,[7] making modern commercial yeast possible, and turning yeast production into a major industrial endeavor. The slurry yeast made by small bakers and grocery shops became cream yeast, a suspension of live yeast cells in growth medium, and then compressed yeast, the fresh cake yeast that became the standard leaven for bread bakers in much of the Westernized world during the early 20th century.
During World War II, Fleischmann's developed a granulated active dry yeast for the United States armed forces, which did not require refrigeration and had a longer shelf-life and better temperature tolerance than fresh yeast; it is still the standard yeast for US military recipes. The company created yeast that would rise twice as fast, cutting down on baking time. Lesaffre would later create instant yeast in the 1970s, which has gained considerable use and market share at the expense of both fresh and dry yeast in their various applications.
In nature, yeast cells are found primarily on ripe fruits such as grapes (before maturation, grapes are almost free of yeasts).[8] Since S. cerevisiae is not airborne, it requires a vector to move.Queens of social wasps overwintering as adults (Vespa crabro and Polistes spp.) can harbor yeast cells from autumn to spring and transmit them to their progeny.[9] The intestine of Polistesdominula, a social wasp, hosts S. cerevisiae strains as well as S. cerevisiae × S. paradoxus hybrids. Stefanini et al. (2016) showed that the intestine of Polistesdominulafavors the mating of S. cerevisiae strains, both among themselves and with S. paradoxus cells by providing environmental conditions prompting cell sporulation and spores germination.
The optimum temperature for growth of S. cerevisiae is 30–35 °C. Two forms of yeast cells can survive and grow: haploid and diploid. The haploid cells undergo a simple lifecycle of mitosis and growth, and under conditions of high stress will, in general, die. This is the asexual form of the fungus. The diploid cells (the preferential 'form' of yeast) similarly undergo a simple lifecycle of mitosis and growth. The rate at which the mitotic cell cycle progresses often differs substantially between haploid and diploid cells.[11] Under conditions of stress, diploid cells can undergo sporulation, entering meiosis and producing four haploid spores, which can subsequently mate. This is the sexual form of the fungus. Under optimal conditions, yeast cells can double their population every 100 minutes.[12][13] However, growth rates vary enormously both between strains and between environments.[14] Mean replicative lifespan is about 26 cell divisions.
In the wild, recessive deleterious mutations accumulate during long periods of asexual reproduction of diploids, and are purged during selfing: this purging has been termed "genome renewal". All strains of S. cerevisiae can grow aerobically on glucose, maltose, and trehalose and fail to grow on lactose and cellobiose. However, growth on other sugars is variable. Galactose and fructose are shown to be two of the best fermenting sugars. The ability of yeasts to use different sugars can differ depending on whether they are grown aerobically or anaerobically. Some strains cannot grow anaerobically on sucrose and trehalose.
All strains can use ammonia and urea as the sole nitrogen source, but cannot use nitrate, since they lack the ability to reduce them to ammonium ions. They can also use most amino acids, small peptides, and nitrogen bases as nitrogen sources. Histidine, glycine, cystine, and lysine are, however, not readily used. S. cerevisiae does not excrete proteases, so extracellular protein cannot be metabolized.
Yeasts also have a requirement for phosphorus, which is assimilated as a dihydrogen phosphate ion, and sulfur, which can be assimilated as a sulfate ion or as organic sulfur compounds such as the amino acids methionine and cysteine. Some metals, like magnesium, iron, calcium, and zinc, are also required for good growth of the yeast. Concerning organic requirements, most strains of S. cerevisiae require biotin. Indeed, a S. cerevisiae-based growth assay laid the foundation for the isolation, crystallisation, and later structural determination of biotin. Most strains also require pantothenate for full growth. In general, S. cerevisiae is prototrophic for vitamins.
Yeast has two mating types, a and α (alpha), which show primitive aspects of sex differentiation. As in many other eukaryotes, mating leads to genetic recombination, i.e. production of novel combinations of chromosomes. Two haploid yeast cells of opposite mating type can mate to form diploid cells that can either sporulate to form another generation of haploid cells or continue to exist as diploid cells. Mating has been exploited by biologists as a tool to combine genes, plasmids, or proteins at will.
The mating pathway employs a G protein-coupled receptor, G protein, RGS protein, and three-tiered MAPK signaling cascade that is homologous to those found in humans. This feature has been exploited by biologists to investigate basic mechanisms of signal transduction and desensitization. Growth in yeast is synchronised with the growth of the bud, which reaches the size of the mature cell by the time it separates from the parent cell. In well nourished, rapidly growing yeast cultures, all the cells can be seen to have buds, since bud formation occupies the whole cell cycle. Both mother and daughter cells can initiate bud formation before cell separation has occurred. In yeast cultures growing more slowly, cells lacking buds can be seen, and bud formation only occupies a part of the cell cycle.

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