• Journal of Life Science
• /
• v.20 no.5
• /
• pp.662-669
• /
• 2010

Lipolytic enzyme-producing bacteria were isolated from edible oil mill effluents on tributyrin agar medium. The shake-flask-scale studies yielded a promising isolate and it was identified as Pseudomonas sp. An OME using various microbiological observations such as cultural, microscopic, and biochemical tests was undertaken and confirmed using PIBWIN bacterial identification software. Lipolytic enzyme production was screened with oils such as sunflower, caster, coconut, tributyrin, and olive. Amongst these, olive oil showed an increased lipase production 6.1 U/ml. In view of the highest lipolytic enzyme production with olive oil, further optimizations were carried out using olive oil as a carbon source. Lipolytic enzyme production was optimized by a conventional 'one variable at a time' approach and the significant factors were further analyzed statistically using response surface methodology (RSM). The effect of physical factors such as incubation time, temperature, initial medium pH, and nutritional factors such as concentration of olive oil and yeast extract were examined for lipase production. Lipolytic enzyme secretion was strongly affected by three variables (incubation time, concentration of yeast extract and olive oil). Therefore, the interaction of these three factors was further optimized using response surface methodology. The optimized conditions of lipase production using response surface methodology yielded a maximum of 9.62 U/ml with optimum conditions for incubation, yeast extract and olive oil concentrations were found to be 48 hr, 0.3 g. and 0.9 ml. respectively.

• Korean Journal of Agricultural Science
• /
• v.14 no.1
• /
• pp.144-155
• /
• 1987

A potent fungus producing milk clotting enzyme with fairly weak proteolytic activity was isolated from various soil and sewage, which the selected strain, SA-101, was identified as Mucor sp. with microbiological characteristics. Its milk clotting enzyme production was maximized when grown on 10g of wheat bran media added to 8ml of tap water containing 0.1M HCl for 60hrs at $30^{\circ}C$. This enzyme production was stimulated by addition of 6% lactose, 0.05% NaCl and reached a maximal level of 9810 unit/g wheat bran. The crude enzyme product could be produced effectively by salting out with ammonium sulfate fractionation and lyophilization. The ratio of milk clotting activity to proteolytic activity of crude enzyme product was lower than Hansen rennet, but resembled to Meito rennet. The optimal temperature of milk clotting activity of crude enzyme product was abound $60^{\circ}C$ on a substrate of 10% reconstituted skim milk containing 1/100M $CaCl_2$.

• KSBB Journal
• /
• v.25 no.5
• /
• pp.453-458
• /
• 2010

The magnetically separable polyaniline nanofiber enzymes were developed for the recycle of enzyme and enhanced enzyme stability. The stability of enzyme was maintained over 90% for 8 days under room temperature and vigorous shaking conditions (200 rpm). The residual activity of immobilized enzyme was over 60% after 8 days incubation at $55^{\circ}C$. Glucose was produced from various polysaccharides, agarose, curdlan, cellulose, and sea weed, using magnetically separable immobilized enzyme. Glucose production rate with curdlan was 1.2 g/(l h) and showed high decomposition rate due to high mass transfer. After 10 times recycle, the residual activity of immobilized enzyme was over 75%. 1 g/L of glucose was produced with 5 mg of immobilized enzymes.

• Microbiology and Biotechnology Letters
• /
• v.23 no.4
• /
• pp.416-424
• /
• 1995

Mechanism of the cyclodextrin (CD) production reaction by cyclodextrin glucanotransferase (CGTase) using swollen extrusion starch as substrate was investigated emphasizing the structural features of starch granule. The degree of gelatinization was identified to be the most representative structural characteristic of swollen starch. The most suitable degree of gelatinization of swollen starch for CD production was around 63.52%. The structural transformation of starch granule during enzyme reaction was also followed by measuring the changes of the degree of gelatinization, microcrystallinity, and accessible and inaccessible portion to CGTase action of residual swollen starch. The adsorption phenomenon of CGTase to swollen starch was also examined under various conditions. The inhibition mechanism of CGTase by various CDs was identified to be competitive, most severely by a-CD. The mechanism elucidated will be used for development of a kinetic model describes CD production reaction in heterogeneous enzyme reaction system utilizing swollen extrusion starch.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.6 no.4
• /
• pp.244-251
• /
• 2001

Over half of all biologically active peptide and peptide hormones are $\alpha$-amidated at their C-terminus, which is essential for their full biological activities. Amidation is accomplished through the sequential reaction of the two enzymes encoded by the single bifunctional, peptidyl-glycine $\alpha$-amidating monooxygenase (PAM or an $\alpha$-amidating enzyme). PAM catalyze the forma - tion of a peptide amide from peptide precursors that include a C-terminal glycine, and requires copper molecular oxygen and ascorbate. PAM is the only enzyme that produces peptide amides in vivo. However various strategies utilizing PAM, carboxypeptidase-Y enzymes, and chemical syn-thesis have been developed for producing peptide amides in vitro. The growing need and impor-tance of peptide amide drugs has highlighted the necessity for a efficient in vitro amidating sys-tem for industrial application for the production of peptide hormones, like calcitonin and oxytocin. This review presents the current situation regarding amidation with a special emphasis on the in-dustrial production or peptide hormones.

• Microbiology and Biotechnology Letters
• /
• v.27 no.5
• /
• pp.370-377
• /
• 1999

Thermo-tolerant bacterium producing the xylanase was isolated from soil and identified as Bacillus pumilus. This strain, named Bacillus pumilus TX703, was able to grow ad produce xylanase at the culture temperature of 5$0^{\circ}C$. The maximum xylanase production was obtained when 1%(w/v) birchwood xylan and 1% (w/v) soytone were used as carbon source and nitrogen source, respectively. The biosynthesis of xylanase was under the catabolite repression induced by glucose in the culture medium, and it was completely inhibited in the presence of 0.2% (w/v) glucose. The maximum activity of xylanase was observed from pH8.0 to 9.0 and from 50 to 6$0^{\circ}C$ and the enzyme was highly heat-stable, whose activity remained was over 50% at 8$0^{\circ}C$, and was quite stable from pH5.0 to 10.0.

• Microbiology and Biotechnology Letters
• /
• v.23 no.2
• /
• pp.187-196
• /
• 1995

In order to produce fuctional chitooligosaccharides, a strain excreting mainly endo-type chitinase suitable for chitooligosaccharides production was newly screened and identified as Aspergillus fumigatus JC-19. The chitinase excretion was repressed in nutrient rich medium but stimulated by colloidal chitin indicating that the chitinase is inducible type enzyme. Maximum secretion of the enzyme was observed at pH 7.0 and 37$\circ$C . The growth and chitinase production patterns of Aspergillus fumigatus JC-19 showed that the cell growth reached maximum after 4-5 days with final chitinase concentration of 0.46 unit per ml. Excreted chitinase was purified by ammonium sulfate precipitation, colloidal chitin adsorption, anion exchange chromatography, and gel filtration, respectively, and measured M.W of 50 KDa. The enzyme reaction carried out both by crude and purified chitinase showed that the purified chitinase accumulated more chitooligosaccharides of 1-6 degree of polymerization than that of crude chitinase.

• Journal of Life Science
• /
• v.9 no.1
• /
• pp.22-28
• /
• 1999

A bacterium producing exo-inulinase was isolated from soil and identified Pseudomonas sp. and named as Pseudomonas sp. NO5. The optimal culture conditions for the efficient production of exo-inulinase from Pseudomonas sp. NO5 were obtained by cultivating with the medium 1$\%$ sucrose, 0.5$\%$ yeast extract, 0.5$\%$ $(NH_4)_2$$HPO_4$, 0.05$\%$ $MgSO_4$ㆍ$7H_2$0, 0.001$\%$ and $FeSO_4$ㆍ$7H_2$0 at $37^{\circ}C$ in initial pH 7.0 for 20 hours. The enzyme was induced maximally in the presence of sucrose or inulin at early stationary phase about 20 hour after cultivation.

• Mycobiology
• /
• v.36 no.3
• /
• pp.167-172
• /
• 2008

Beef luncheon meat is one of the most popular meals in several countries in the world including Egypt. Thirty one fungal species and 3 species varieties were recovered from 30 samples of beef luncheon meat collected from different supermarkets in Qena. Alternaria, Aspergillus, Emericella, Mucor, Mycosphaerella, Penicillium and Rhizopus were the most common genera on the two types of media. From the above genera, the most prevalent species were Alternaria alternate, Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Emericella nidulans, Mucor racemosus, Mycosphaerella tassiana, Penicillium chrysogenum and Rhizopus stolonifer. Screening of fungi for their abilities to produce lipase enzyme showed that, ten isolates represented 32.26% of total isolates appeared high lipase production, while sixteen isolates (51.61%) were moderate and 5 isolates (16.13%) were low producers. Aspergillus niger, Fusarium oxysporum and Nectria haematococca produced the highest amount of lipase enzyme, so these fungi were used in further studies. The incorporation of five food preservatives (Disodium phosphate, sodium benzoate, citric acid, potassium sorbate and sodium citrate) individually in the culture medium of lipase production exhibited an inhibitive effect on the mycelial growth and enzyme production by Aspergillus niger, Fusarium oxysporum and Nectria haematococca.

• Korean Journal of Microbiology
• /
• v.14 no.2
• /
• pp.49-49
• /
• 1976

Enzyme activities, such as glucoamylase dextrinogenic amylase, cellulase, acid protase and neutral protease, of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their enzyme activities are surveyed from taxonomical, ecological and physiological viewpoint. Effect of carbon sources and phytohormones on the amylalse production of Rhizopus are also measured. Among the 735 strains of Phizopus isolated, strain number 587 exhibiting most prominent dextrinogenic amylase and netral protease activity is selected as the best strain, and the strain number 673, 108, 329, 165 and 728 are seleted for their predominant cellulase, acid protease, glucoamylase, dextrinogenic amylase and neutral protease activities, respectively. R.acidus and R.nigricans which exhibited relatively higher callulalse activity, showed lower activities for both amylase. R.tritici exhibited higher protease activity. The relations between activities and various substrates of wild strains are not outstnading difference, although the strains isolated from inland region exhibited more or less higher amylase and cellulase activities, than those of coast region, generally. Lactose and dextrin are most effective carbon sources for glucoamylase and dextrinogenic amylase production of the Rhizopus niveus, respectively. Although all phytohormones tested are effective for production of amylase by the Rhizopus strains, except nicotinamide for glucoamylase production, biotin and ascorbate are most effective for dextrinogenic amylase and glucoamylase production, respectively.