• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.536-539
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• 1988

A mutant of Bacillus subtilis with a defective cdd gene encoding deoxycytidine-cytidine deaminase (EC 3.5.4.5) has been characterized genetically. The genetic lesion, cdd, causing the altered deoxycytidine-cytidine deaminase was mapped at 225 min on the linkage map of B. subtilis by AR9 transduction, Transductional analysis of the cdd region established the gene order in clockwise as trp-lys-cdd-aroD. The cdd gene was linked 72% with the aroD and 20% with the lys.

• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.59-68
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• 2023

Xylanase is an industrially relevant enzyme used for the production of xylobiose and xylose. Various methods are used to enhance the microbial yield of xylanase. In the present study, co-culturing of Bacillus subtilis and Bacillus pumilus were investigated using submerged fermentation for xylanase production, which was markedly increased when sal, sagwan, newspaper, wheat bran, and xylan were used as single carbon sources. Maximum xylanase production was reported after 5 days of incubation in optimized media at pH 7.0 and 37℃, resulting in 2.69 ± 0.25 µmol/min by coculture. The 1:1 ratio of sal and sagwan in optimized production media was shown to be suitable for xylanase synthesis in submerged fermentation (SMF). In comparison to mono-culture using B. pumilus and B. subtilis, co-culturing resulted in an overall 3.8-fold and 2.15-fold increase in xylanase production, respectively.

• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.93-98
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• 2023

Nuruk is a starter culture of Korea manufactured by spontaneous fermentation of grains. We isolated bacteria of the genera Bacillus and Staphylococcus, and lactic acid bacteria (LAB) from eight commercial nuruk samples collected from four districts of Korea using selective agar media and identified them based current taxonomic standards. Bacillus was detected in all samples, but Staphylococcus or LAB were not detected in three samples. In seven samples, except one sample scored the highest cell number of LAB, Bacillus and Staphylococcus were counted as the highest and the lowest numbers, respectively. Six species of Bacillus were identified, and B. subtilis, B. velezensis, and B. licheniformis were predominant species. Nine species of coagulase-negative Staphylococcus were identified, and the predominance of S. pseudoxylosus and S. saprophyticus was confirmed. Ten species of LAB including Enterococcus, Lactobacillus and close relatives, Pediococcus, and Weissella were identified. P. pentosaceus was identified as the predominant species.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.21-27
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• 2009

A study was carried out to find out the methodology of biological treatment for wastes and wastewater caused by an organophosporus insecticide, fenitrothion, using fenitrothion-degrading microorganism. A fenitrothion-degrading microorganism was isolated by using a selective nutrient broth (NB) medium including fenitrothion, and identified to Bacillus sphaericus NFol based on its morphological and biochemical characteristics. Further, investigation was processed to determine the optimal culture conditions degrading fenitrothion in NB medium by using the NFo1 strain. As results, the cultural conditions determined for temperature, initial pH and inoculum for the optimum growth of the strain and degradation of fenitrothion, which has a exact co-relationship between both of them, were $35^{\circ}C$, 7.5 and 1.5 at $OD_{660}$ value, respectively. In this conditions, fenitrothion could be degraded within 5 days over 90% at the high concentrations of fenitrothion, upto 200 mg/L.

• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.148-153
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• 1989

A strain of alkalophilic Bacillus sp. YC-335 has been isolated from soil. The strain was capable of producing large amount of cyclodextrin glycosyl transferase (CGTase) in the culture broth. The preferable medium composition has been determined to be as follows : 1.5% soluble starch, 5% corn steep liquor, 0.1% $K_2$HPO$_4$, 0.02%mgSO$_4$.7$H_2O$, 1% CaCO$_3$and 1% Na$_2$CO$_3$(pH 10.3). The highest enzyme production was observed after 48 hours of cultivation at 31$^{\circ}C$. The optimum pH and temperature for the activity of crude enzyme were 6.0 and 5$0^{\circ}C$, respectively. The enzyme was stable between pH 5 and 9, and upto 5$0^{\circ}C$. The enzyme converted starch into $\alpha$-, $\beta$- and ${\gamma}$-CD in the relative amounts of 1:10:1.5, respectively.

• Microbiology and Biotechnology Letters
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• v.36 no.2
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• pp.115-120
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• 2008

Bacterial populations from the rhizosphere were obtained and the efficacy of the bacterial wilt suppression, root colonizing ability and resistance to three kinds of chemical pesticides were assayed. According to these results, SKU48-2 was selected as a potential biological agent to control the bacterial wilt caused by Ralstonia solanacearum. SKU48-2 strain at $10^8CFU/ml$ inoculum was able to suppress the bacterial wilt up to 60% in greenhouse trials. Also, the resistance of SKU48-2 to chemical pesticides make possible to use in combination with chemical pesticides for the control of bacterial wilt. Three different powder formulations of SKU48-2 were developed. The shelf-life of powder formulations was effective up to 6 months of storage. Unformulated bacterial suspension could not be stored for 2 weeks, at which time cell viability was completely lost. According to 16S rDNA sequence data, the SKU48-2 stain was identified as Bacillus subtilis.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.273-276
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• 1989

The isolate SPO 3, an oligosporogenous and crystalliferous mutant, which was isolated from Bacillus thuringiensig subsp, israelensis by heat treatment at 42$^{\circ}C$ for 24 hit. The $\delta$-endotoxin of the mutant had a relatively low hemolytic activity on human red blood cells; the $\delta$-endotoxin of the mutant had 25 times less hemolytic activity compared to that of wild strain. The loss of 28 KDa hemolytic protein subunit in $\delta$-endotoxin of the mutant was confirmed by means of double immunodiffusiori, immunoelectrophoresis, and SDS-PAGE.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.348-353
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• 2008

With the aim to explore the possible role of phosphate-solubilizing bacteria in soil, we conducted a survey of phosphate-solubilizing microorganisms colonizing in upland and plastic film house soils. Soil EC, pH, organic matter, available phosphate, exchangeable cation such as potassium, calcium and magnesium, and total P of plastic film house soils were higher than those of upland soils. Phosphate-solubilizing bacteria population was higher in plastic film house soils than upland soils, but species of phosphate-solubilizing bacteria was more diverse in the upland soils than the plastic film house soils. There was significant positive correlation between phosphate solubilization and phosphate-solubilizing bacteria in soils. Bacillus, Cedecea, Brevibacillus, Paenibacillus, Pseudomonas, Serratia spp. were isolated from upland soils and Bacillus and Cellulomonas spp. were from plastic film house soils.

• Korean Journal of Microbiology
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• v.33 no.2
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• pp.136-141
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• 1997

To elucidate whether there are bacteria excreting proteases in Korean traditional fermented food, soybean paste (Doen-Jang) or not, well growing bacteria with halos were isolated on the qkim milk agar media. The strains were identified as Bacillu, cereus JH-1, B. cereus SH-5, B. cereus SH-7 through various physiological and biochemical tests, VlTEK system, and MIDI system. The extracellular proteases of the strain JH-1, and SH-5, were optimal at pH 9, 40^{\circ}C.$, and the protease of strain SH-7 at pH 8 and 50^{\circ}C.$. Also hemolysis activities of the three strains were observed on the hlood agar media.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.16-17
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• 2005