• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.4
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• pp.367-371
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• 2005

About 3,000 bacterial colonies with esterase activities were isolated from soil samples by enrichment culture and halo-size on Luria broth-tributyrin (LT) plates. The colonies were assayed for esterase activity in microtiter plates using enantiomerically pure (R)- and (S)-2-phenylbutyric acid resorufin ester (2PB-O-res) as substrates. Two enantioselective strains (JH2 and JH13) were selected by the ratio of initial rate of hydrolysis of enantiomerically pure (R)- and (S)-2-PB-O-res. When cell pellets were used, both strains showed high apparent enantioselectivity ($E_{app}>100$) for (R)-2PB-O-res and were identified as Exiguobacterium acetylicum. The JH13 strain showed high esterase activity on p-nitrophenyl acetate (pNPA), but showed low lipase activity on p-nitrophenyl palmitate (pNPP). The esterase was located in the soluble fraction of the cell extract. The crude intracellular enzyme preparation was stable at a pH range from 6.0 to 11.0.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.57-63
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• 2003

Using fungal (Fusarium solani f. pisi) and bacterial (Pseudomonas mendocina) cutinases, the initial hydrolysis rate of p-nitrophenyl esters was systematically estimated for a wide range of enzyme and substrate concentrations using a 96-well microplate reader. Both cutinases exhibited a high substrate specificity; i.e. a high hydrolytic activity on p-nitrophenyl butyrate (PNB), yet extremely low activity on p-nitrophenyl palmitate (PNP). When compared to the hydrolysis of PNB and PNP by other hydrolases [lipases and esterases derived from different microbial sources, such as bacteria (Pseudomonas cepacia, Psedomonas furescens, Baciilus stearothermophilus), molds (Aspeillus niger, mucor miehei), and yeasts (Candida rugosa, Candida cylindracea)], the above substrate specificity would seem to be a unique characteristic of cutinases. Secondly, the hydrolytic activity of the cutinases on PNB appeared much faster than that of the other hydrolytic enzymes mentioned above. Furthermore, the current study proved that even when the cutinases were mixed with large amounts of other hydrolases (lipases or esterases), the Initial hydrolysis rate of PNB was determined only by the cutinase concentration for each PNB concentration. This property of cutinase activity would seem to result from a higher accessibility to the substrate PNB, compared with the other hydrolytic enzymes. Accordingly, these distinct properties of cutinases may be very useful in the rapid and easy isolation of various natural cutinases with different microbial sources, each of which may provide a novel industrial application with a specific enzymatic function.

• Mycobiology
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• v.50 no.6
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• pp.408-419
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• 2022

Filamentous fungi that could be classified into Aspergillus flavus/oryzae were isolated from traditionally fermented meju commercially available in Korea. The samples were analyzed for aflatoxin B1 and ochratoxin A contamination by HPLC; however, no toxin was detected. In addition, fungal and bacterial metagenomic sequencing were performed to analyze the microbial distribution in the samples. The results revealed that the distribution and abundance of fungi and bacteria differed considerably depending on the production regions and fermentation conditions of the meju samples. Through morphological analysis, ITS region sequencing, and assessment of the aflatoxin-producing ability, a total of 32 A. flavus/oryzae strains were identified. PCR analysis of six regions with a high mutation frequency in the aflatoxin gene cluster (AGC) revealed a total of six types of AGC breaking point patterns. The A. flavus/oryzae strains did not exhibit the high amylase activity detected in the commercial yellow koji strain (starter mold). However, their peptidase and lipase activities were generally higher than that of the koji isolates. We verified the safety of the traditionally fermented meju samples by analyzing the AGC breaking point pattern and the enzyme activities of A. flavus/oryzae strains isolated from the samples. The isolated strains could possibly be used as starter molds for soybean fermentation.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.119-127
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• 2014

The affiliations and physiological characteristics of culturable bacteria isolated from the sediments of Ross Sea, Antarctica were investigated. Sixty-three isolates obtained by cultivation were grouped into 21 phylotypes affiliated with the phyla Actinobacteria and Bacteroidetes and with the classes Alphaproteobacteria and Gammaproteobacteria by phylogenetic analysis of 16S rRNA gene sequences. Based on phylogenetic analysis (<98.65% sequence similarity), approximately 49% of total isolates represented potentially novel species or genus. Among them, extracellular protease, lipase, and exopolysaccharide activities at $10^{\circ}C$ or $20^{\circ}C$ were detected in approximately 46%, 25%, and 32% of the strains, respectively. Forty-three isolates produced at least one type of extracellular material and 21 of them produced at least two extracellular protease, lipase, and/or exopolysaccharides. Our findings indicate that culturable bacterial diversity present within the marine sediments of Ross Sea, Antarctica may contribute to the hydrolysis of the major organic constituents which is closely related with carbon and nitrogen cycling in this environment.

• Research in Plant Disease
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• v.22 no.2
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• pp.81-93
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• 2016

Out of plant-associated bacteria, certain plant growth-promoting bacteria (PGPB) have been reported to increase plant growth and productivity and to elicit induced resistance against plant pathogens. In this study, our objective was to broaden the range of applications of leaf-colonizing PGPB for foliar parts of road tress and pepper. Total 1,056 isolates of endospore-forming bacteria from tree phylloplanes were collected and evaluated for the enzymatic activities including protease, lipase, and chitinase and antifungal capacities against two fungal pathogens, Colletotrichum graminicola and Botrytis cinerea. Fourteen isolates classified as members of the bacilli group displayed the capacity to colonize pepper leaves after spraying inoculation. Three strains, 5B6, 8D4, and 8G12, and the mixtures were employed to evaluate growth promotion, yield increase and defence responses under field condition. Additionally, foliar application of bacterial preparation was applied to the road tress in Yuseong, Daejeon, South Korea, resulted in increase of chlorophyll contents and leaf thickness, compared with non-treated control. The foliar application of microbial preparation reduced brown shot-hole disease of Prunus serrulata L. and advanced leaf abscission in Ginkgo biloba L. Collectively, our results suggest that leaf-colonizing bacteria provide potential microbial agents to increase the performance of woody plants such as tree and pepper through spray application.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.735-741
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• 2011

Bealmijang is a short-term fermented regional product that is prepared with soybean and extra ingredients. In this study, starter strain candidates were screened from Bealmijang for fermented soybean paste products. Twenty one bacterial strains producing extracellular enzymes (amylase, cellulase, protease, xylanase and lipase) were isolated from Bealmijang, buckwheat sokseongjang. The isolates were assessed for fibrinolytic and antibacterial activities, and salt tolerance. Strain HJ18-4, identified as Bacillus subtilis (AB601598) by biochemical properties (89.6%) and 16S rDNA sequencing (100%), showed the highest enzymatic, fibrinolytic, and antibacterial activities among the isolates. Although the growth of HJ18-4 was inhibited by the increase of NaCl concentration, the growth still exceeded that of B. subtilis KACC 10114 at 5% and 10% NaCl. These results suggest that B. subtilis HJ18-4 is suitable as a starter for soybean paste manufacture.

• Journal of Life Science
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• v.27 no.11
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• pp.1381-1392
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• 2017

This review described solvent-tolerant lipases and their potential industrial, biotechnological and environmental impacts. Although organic solvent-tolerant lipase was first reported in organic solvent-tolerant bacterium, many organic solvent-tolerant lipases are in not only solvent-tolerant bacteria but also solvent-intolerant bacterial and fungal strains, such as the well-known Bacillus, Pseudomonas, Streptomyces and Aspergillus strains. As these lipases are not easily inactivated in organic solvents, there is no need to immobilize them in order to prevent an enzyme inactivation by solvents. Therefore, the solvent-tolerant lipases have the potential to be used in many biotechnological and biotransformation processes. With the solvent-tolerant lipases, a large number insoluble substrates become soluble, various chemical reactions that are initially impossible in water systems become practical, synthesis reactions (instead of hydrolysis) are possible, side reactions caused by water are suppressed, and the possibility of chemoselective, regioselective and enantioselective transformations in solvent and non-aqueous systems is increased. Furthermore, the recovery and reuse of enzymes is possible without immobilization, and the stabilities of the lipases improve in solvent and non-aqueous systems. Therefore, lipases with organic-solvent tolerances have attracted much attention in regards to applying them as biocatalysts to biotransformation processes using solvent and non-aqueous systems.

• Journal of Aquaculture
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• v.11 no.4
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• pp.495-503
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• 1998

The present study investigated the effects of Bisroot, that contains live bacteria (Bacillus polyfermenticus, Bacillus mesentericus, Streptococcus faecalis, & Bifidobacterium breve) and digestive enzymes (protease, lipase), on the growth, body composition and immune response of Nile tilapia fingerlings. One percent of the Bisroot was added to the experimenta feed. All exprimental fish were fed for 60 days. The weigh gains among the experimental fish were not significntly different (P>0.05). Hematocrit value, hemoglobin, total protein, glucose, GOT, and GPT were unaffected by Bisroot treatment. However, it was observed that glucose, GOT, and GPT value in the fish that were fed Bisroot, were lower than the control. The complement activity ($CH_50$) tended to be significantly increased by Bisroot treatment, but not lysozyme activity. Phagocytosis and respiratory burst activities of macrophages in the head kidney were enhanced by Bisroot. Therefore, the Bisroot diet enhances the cellular immune activities were enhanced by Bisroot. Therefore, the Bisroot diet enhances the cellular immune activities of non-specific immune responses. When fish were challenged with a virulent strain of Edwardsiella tarda, the Bisroot treated fish were more resistant than the control. The present results suggest that the introduction of Bisroot into the diet of Nile tilapia could increase their resistance against bacterial infection, reduce fish mortality, and offers economic benefits.

• Journal of Life Science
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• v.25 no.2
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• pp.180-188
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• 2015

The bacterial strain isolated from Kimchi showed antibacterial activity against Micrococcus luteus IAM 1056. The selected strain was identified as Lactococcus lactis by 16S rRNA nucleotide sequence analysis and named as Lactococcus sp. KD 28. The treatment of culture supernatant with proteinase K removed antibacterial activity, indicating its proteinaceous nature, a bacteriocin. This bacteriocin was sensitive to hydrolytic enzymes such as ${\alpha}$-chymotrypsion, trypsin, proteinase K, lipase, ${\alpha}$-amylase and subtilisin A. The bacteriocin was highly thermostable and resistant to heating at $80^{\circ}C$ for up to an hour but 50 % of the total activity was remained at $100^{\circ}C$ for 30 min. The pH range from 2.0 to 8.0 had no effect on bacteriocin activity and it was not affected by solvents such as acetonitrile, isopropanol, methanol, chloroform and acetone up to 50% concentration. The bacteriocin showed antibacterial activity against M. luteus IAM 1056, Lactobacillus delbrueckii subsp. lactis KCTC 1058, Enterococcus faecium KCTC 3095, Bacillus cereus KCTC 1013, B. subtilis KCTC 1023, Listeria ivanovii subsp. ivanovii KCTC 3444, Staphylococcus aureus subsp. aureus KCTC 1916, B. megaterium KCTC 1098 and B. sphaericus KCTC 1184. The bacteriocin was purified through ammonium sulfate concentration, SP-Sepharose chromatography and RP-HPLC. The molecular weight was estimated to be about 3.4 kDa by tricine-SDS-PAGE analysis.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1144-1151
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• 2013

In this study, protein domains with cellulase activity in goat rumen microbes were investigated using metagenomic and bioinformatic analyses. After the complete genome of goat rumen microbes was obtained using a shotgun sequencing method, 217,892,109 pair reads were filtered, including only those with 70% identity, 100-bp matches, and thresholds below $E^{-10}$ using METAIDBA. These filtered contigs were assembled and annotated using blastN against the NCBI nucleotide database. As a result, a microbial community structure with 1431 species was analyzed, among which Prevotella ruminicola 23 bacteria and Butyrivibrio proteoclasticus B316 were the dominant groups. In parallel, 201 sequences related with cellulase activities (EC.3.2.1.4) were obtained through blast searches using the enzyme.dat file provided by the NCBI database. After translating the nucleotide sequence into a protein sequence using Interproscan, 28 protein domains with cellulase activity were identified using the HMMER package with threshold E values below $10^{-5}$. Cellulase activity protein domain profiling showed that the major protein domains such as lipase GDSL, cellulase, and Glyco hydro 10 were present in bacterial species with strong cellulase activities. Furthermore, correlation plots clearly displayed the strong positive correlation between some protein domain groups, which was indicative of microbial adaption in the goat rumen based on feeding habits. This is the first metagenomic analysis of cellulase activity protein domains using bioinformatics from the goat rumen.