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Alginate and its derivatives are annually produced approximately 30,000 tons or more and are applied to various industries as they are natural polymers. The global market for alginate and its derivatives has been growing steadily. There is little research compared to other enzymes produced through biomass degradation or modification. An alginate lyase, MtAl138, from Microbulbifer thermotolerans DAU221 was cloned and identified in Escherichia coli BL21 (DE3). MtAl138 contains a highly conserved motif (R538TELR, Q607IH609, and YFKAGVY716NQ), which indicates that it belongs to the polysaccharide lyase family 7 (PL7). MtAl138, with a molecular weight of 77 kDa worked optimally at 45 °C and pH 7.4. MtAl138 showed twice as much activity as when there was no NaCl when there was between 100 and 600 mM NaCl. Moreover, its activity increased in organic solvents such as benzene, hexane, methanol, and toluene. Based on the thin layer chromatography analyses, MtAl38 is an endo-type enzyme that produces di-, tri-, or tetrasaccharides from polyG and polyM. This study provided that MtAl138 is an endoenzyme that showed outstanding enzymatic activity at concentrated salt solutions and organic solvents, which makes it a reasonably attractive enzyme for use in various industries.

A marine bacterium, Olleya aquimaris DAU311, was isolated from Goraebul beach in the Republic of Korea. This strain had β-glucosidase activity on Luria–Bertani esculin plates. The β-glucosidase, oabgl84, was isolated, cloned, and sequenced, based on fosmid library. The gene encoded novel β-glucosidase and consisted of an open reading frame of 2304 bp, which encodes 768 amino acids. The deduced amino acid sequence had 99% identity to Olleya sp. VCSM12, 84% identity to Olleya marilimosa, and 78% similarity to Lacinutrix sp. Hel_I_90. OaBGL84 belongs to the glycoside hydrolase family 3, and it was visualized using SDS-PAGE, approximately 84 kDa. The optimal temperature and pH of OaBGL84 were analyzed as 40 °C and 6.0, respectively, using pNPG as substrate. The Km and Vmax values for OaBGL84 were 1.35 mM and 25.3 μM/s, respectively. Furthermore, OaBGL84 activity was completely inhibited by Cu2+ and Hg2+ ions. OaBGL84 demonstrated extraordinary stability until 50% (v/v) benzene, n-hexane, or toluene. These results indicate that OaBGL84 is useful candidate to degrade cellulose or soy isoflavone in the organic solvents for various biotechnological applications.

Backgroundβ-Glucosidases have attracted considerable attention due to their important roles in various biotechnological processes such as cellulose degradation to make energy and hydrolysis of isoflavone.Microbulbifer thermotolerans(M. thermotolerans) is isolated from deep-sea sediment and has not been researched much yet. As a potential candidate for a variety of biotechnological industries,β-glucosidases from the novel bacterial species should be researched extensively.Methodsβ-Glucosidase, MtBgl85, fromM. thermotoleransDAU221 was purified by His-tag affinity chromatography and confirmed by SDS-PAGE and zymogram. Its biochemical and physiological properties, such as effects of temperature, pH, metal ions, and organic solvents, substrate specificity, and isoflavone hydrolysis, were investigated.ResultsM. thermotoleransDAU221 showedβ-glucosidase activity in a marine broth plate containing 0.1% esculin and 0.25% ammonium iron (III) citrate. Theβ-glucosidase gene,mtbgl85, was isolated from the whole genome sequence ofM. thermotoleransDAU221. Theβ-glucosidase gene was 2,319 bp and encoded 772 amino acids. The deduced amino acid sequence had a 43% identity with OaBGL84 fromOlleya aquimarisand 35% and 32% identity with to CfBgl3A and CfBgl3C fromCellulomonas fimiamong bacterial glycosyl hydrolase family 3, respectively. The optimal temperature of MtBgl85 was 50 °C and the optimum pH was 7.0. MtBgl85 activity was strongly reduced in the presence of Hg2+and Cu2+ions. As a result of measuring the activity at various concentrations of NaCl, it was confirmed that the activity was maintained up to the concentration of 1 M, but gradually decreased with increasing concentration. MtBgl85 showed higher enzyme stability at non-polar solvents (high LogPow) than polar solvents (low LogPow). The hydrolyzed products of isoflavone glycosides and arbutin were analyzed by HPLC.

Strain AP01 was isolated for the biological cypermethrin degradation from soil and sediment in Busan. This strain was identified on the basis of phylogenetic analysis of the 16s rDNA sequence and assigned as Bacillus amyloliquefaciens AP01. AP01 could degrade about 45% of cypermethrin in the mineral medium at 30 o C and 180 rpm for 5 days. Furthermore when 2% glucose was added in the medium, the degradation rate of cypermethrin by strain AP01 was increased upto about 60%. Therefore, AP01 may serve as a promising strain in the bioremediation of soil polluted with cypermethrin.

Background The ability to use organic solvents in enzyme reactions offers a number of industrially useful advantages. However, most enzymes are almost completely inactive in the presence of organic solvents. Thus, organic solvent-tolerant enzymes have potential applications in industrial processes. Results A chitinase gene from Microbulbifer thermotolerans DAU221 (mtch509) was cloned and expressed in Escherichia coli BL21 (DE3). The molecular weight of the expressed MtCh509 protein was approximately 60 kDa, and it was purified by His-tag affinity chromatography. Enzymatic assays showed that the optimum temperature for MtCh509 chitinase activity was 55 °C, and the enzyme was stable for 2 h at up to 50 °C. The optimum pH for MtCh509 activity was in the sub-acidic range, at pH 4.6 and 5.0. The activity of MtCh509 was maintained in presence of 1 M salt, gradually decreasing at higher concentrations, with residual activity (20%) detected after incubation in 5 M salt. Some organic solvents (benzene, DMSO, hexane, isoamyl alcohol, isopropyl alcohol, and toluene; 10–20%, v/v) increased the reactivity of MtCh509 relative to the aqueous system. When using NAG3, as a substrate, MtCh509 produced NAG2 as the major product, as well as NAG4, demonstrating that MtCh509 has transglycosylation activity. The K m and V max values for MtCh509 using colloidal chitin as a substrate were 9.275 mg/mL and 20.4 U/mg, respectively. Thus, MtCh509 could be used in extreme industrial conditions. Conclusion The results of the hydrolysate analysis and the observed increase in enzyme activity in the presence of organic solvents show that MtCh509 has industrially attractive advantages. This is the first report on an organic solvent-tolerant and transglycosylating chitinase from Microbulbifer species.

A sequence-based polymerase chain reaction (PCR) was employed to screen fibrinolytic enzymes from soil metagenomes. A basic alignment search tool (BLAST) sequence homology analysis of 15 positive amplicons indicated a high degree of nucleotide sequence identity (>98%) to a fibrinolytic enzyme, nattokinase in Bacillus sp. Among the positive clones, KSL79_FE was selected for further characterization. Sequence analysis showed that its open reading frame (ORF) consisted of 1,146 nucleotides encoding 375 amino acids, of which two differed from the nattokinase (T268S and V298A). To overexpress the fibrinolytic enzyme, we transformed the plasmid pET28a/KSL79_FE into E. coli BL21 Codon (+) cells, leading to yield optimal expression by using a 9-h induction with 30 uM isopropyl thio-β-D-galactoside (IPTG) at an OD600 of 0.5. The resulting KSL79_FE enzyme exhibited caseinolytic and fibrinolytic activities similar to those of nattokinase. In contrast to the nattokinase which showed the optimal conditions for proteolytic activity at 37°C and pH 8.0, KSL79_FE enzyme displayed maximal proteolytic activity at 50°C and pH 9.0. In addition, the enzyme activity of KSL79_FE was inhibited by Zn+2 ions, but not by Cu+2 ions, not similar to nattokinase. The two residues varied from amino acid sequence of nattokinase which might change the biochemical properties and optimal enzyme activity of KSL79_FE. Key words: Nattokinase, proteolytic activity, metagenome, fibrinolytic activity, cloning and expression.

Paenibacillus xylanilyticus KJ-03 isolated from konjac field, showed β-glucosidase activity on tryptic soy agar plate supplemented with 0.1 % esculin and 0.25 % ferric ammonium citrate. A genome library was constructed to obtain the β-glucosidase gene and a recombinant clone, pGlc2-3 was selected. The 2,247 bp gene encoding KJ-03 β-glucosidase consisted of 749 amino acids. The deduced amino acids of BglA were 61 % homologous with that of the β-glucosidase from Bacillus cereus AH1272, which belongs to the glycoside hydrolase family 3. His-tagged β-glucosidase was purified by using His-Trap column and characterized. KJ-03 β-glucosidase was showed as a single band with about 82 kDa on SDS-PAGE. The purified enzyme has optimal activity at 20 °C and pH 7.0 using p-NPβG and 72 % of the maximal activity was still remaining at 10 °C. The β-glucosidase has optimal activity at low temperatures indicating that it is a cold-active enzyme. The substrate specificity showed that the purified enzyme hydrolyzed aryl β-glucoside substrates and isoflavones such as daidzin and genistin.

Glucoamylase (EC 3.2.1.3) is an important group of enzymes in starch processing, also referred to as amyloglucosidases, which are exo-acting amylases that release glucose from the nonreducing end of starch and related oligosaccharides. The glucoamylase newly isolated from the Aspergillus niger FME) was reported for the first time. This enzyme was produced by detergent-mediated release and purified to ∼9.11 fold using Sephadex-G 100 and ion-exchange chromatography. Molecular mass of the glucoamylase was ∼36 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The product of starch hydrolysis, analysed by thin-layer chromatography, showed the presence of glucose. The optimum pH and temperature for glucoamylase activity was 5.0 and 45°C, respectively. The Km and Vmax values of the enzyme were also determined using soluble starch as substrate as 94 μg/mL and 39.02 U/mg, respectively. Moreover, glucoamylase was slightly activated by presence of Na and K ions and 10–20% inhibition was observed in presence of Zn2+, Sn2+, Mg2+, Ni2+, Mn2+, and almost 80% with Cu2+ ions, whereas the presence of ethylene diamine tetra acetic acid (EDTA) did not show significant inhibition. Glucoamylase, also assayed for surfactant property, shows significant surfactant tolerance at high concentrations of detergent and can retain 90% of its activity. Finally, secondary structure analysis of glucoamylase by circular dichroism spectroscopy showed the presence of 48% α-helix, 11% β-sheet, and 41% random structure.

Paenibacillus xylanilyticus KJ-03 was isolated from soil samples obtained from a field with Amorphophallus konjac plants. A gene encoding xylanase was isolated from KJ-03 and cloned using a fosmid library. The xynA gene encodes xylanase; it consists of 1,035 bp and encodes 345 amino acids. The amino acid sequence deduced from the P. xylanilyticus KJ-03 xylanase showed 81% and 69% identities with those deduced from the P. polymyxa E681 and Paenibacillus sp. HPL-001 xylanases, respectively. The xynA gene comprises a single domain, consisting of a catalytic domain of the glycosyl hydrolase (GH) 10 family. The xynA gene was expressed in Escherichia coli BL21 (trxB), and the recombinant xylanase was purified by Niaffinity chromatography. The purified xylanase showed optimum activity with birchwood xylan as a substrate at 40°C and pH 7.4. Treatment with Mg(2+) and Li(+) showed a slight decrease in XynA activity; however, treatment with 5 mM Cu(2+) completely inhibited its activity. The results of the thin layer chromatography analysis indicated that the major hydrolysis product was xylobiose and small amounts of xylose and xylotriose. XynA showed increased activity with oat spelt xylan and birchwood xylan, but showed only slight activity with locust bean gum.

Cellulophaga lytica DAU203 (KACC 19187), isolated from the marine sediment in Korea, has a strong ability to degrade agar. The genome of C. lytica DAU203 contains a single chromosome that is 3,952,957bp in length, with 32.02% G+C contents. The genomic information predicted that the DAU203 has the potential to be utilized in various enzymatic industries.

The objective of this study was to develop a mineral phosphate-solubilizing bacterium as a biofertilizer. A mineral phosphate-solubilizing bacterium HR-1019 was isolated from cultivated soils. It was identified as Bacillus subtilis by 16S rDNA analysis. The phosphate-solubilizing activities of the HR-1019 strain against three types of insoluble phosphate, hydroxyapatite, tri-calcium phosphate, and aluminum phosphate were quantitatively determined. When 5% of glucose concentration was used as a carbon source, the strain showed marked mineral phosphate-solubilizing activity. Mineral phosphate solubilization was directly related to pH drop in the culture solution of the strain. The pathogenic activity and antifungal effects of the HR-1019 strain were measured inclear zones formed in PDA media.

The purpose of this research was to investigate the production and characterization of alkaline protease from Micrococcus sp. PS-1 newly isolated from seawater. Micrococcus sp. PS-1 was grown in Luria- Bertani (LB) medium. Its optimal temperature and pH for growth were 30°C and 7.0, respectively. The effect of nitrogen sources was investigated on optimal enzyme production. A high level of alkaline protease production occurred in LB broth containing 2% skimmed milk. The protease was purified in a 3-step procedure involving ultrafiltration, acetone precipitation, and dialysis. The procedure yielded a 16.43-purification fold, with a yield of 54.25%. SDS-PAGE showed that the enzyme had molecular weights of 35.0 and 37.5 kDa. Its maximum protease activity was exhibited at pH 9.0 and 37°C, and its activity was stable at pH 8.0?11.0 and 25?37°C. The protease activity was strongly inhibited by PMSF, EDTA, and EGTA. Taken together, the results demonstrate that the protease enzyme from Micrococcus sp. PS-1 probably belongs to a subclass of alkaline metallo-serine proteases.

A biofertilizer, BIOACTIVE, was manufactured by N-acetyl-thioproline (ATCA) and mineral phosphate solubilizing bacteria. The growth promoting effect of the biofertilizer on lettuce was evaluated under three different pot conditions, and its stability was assessed in the field. According to the results of the pot experiments, plant growth was improved compared with that of control: 128%, 122%, and 153% for the leaf number, leaf length, and leaf mass, respectively. Applying the manufactured biofertilizer increased the concentration of phosphate: 118% and 132% in the cultivation soil and plant cells, respectively. These show that BIOACTIVE may have potential as an effective biofertilizer in agriculture.

Microbulbifer thermotolerans DAU221 was preliminary isolated from the marine sediment samples in the Republic of Korea. Here, we present the complete genome sequence of M. thermotolerans DAU221, which consisted of 3,938,396 base pairs with a GC content of 56.57%. This genomic information should help us find the industrially useful enzymes.

The gene encoding the cyclodextrin glucanotransferase (CGTase, EC2.4.1.19) of Paenibacillus illinoisensis was isolated, cloned, sequenced and expressed in Escherichia coli. Sequence analysis showed that the mature enzyme (684 amino acids) was preceded by a signal peptide of 34-residues. The deduced amino acid sequence of the CGTase from P. illinoisensis ZY-08 exhibited highest identity (99 %) to the CGTase sequence from Bacillus licheniformis (P14014). The four consensus regions of carbohydrate converting domain and Ca2+ binding domain could be identified in the sequence. The CGTase was purified by using cold expression vector, pCold I, and His-tag affinity chromatography. The molecular weight of the purified enzyme was about 74 kDa. The optimum temperature and pH of the enzyme were 40 °C and pH 7.4, respectively. The enzyme activity was increased by the addition of Ca2+ and inhibited by Ba2+, Cu2+, and Hg2+. The K m and V max values calculated were 0.48 mg/ml and 51.38 mg of β-cyclodextrin/ml/min. The ZY-08 and recombinant readily converted soluble starch to β-cyclodextrin but ZY-08 did not convert king oyster mushroom powder and enoki mushroom powder. However the recombinant CGTase converted king oyster mushroom powder and enoki mushroom powder to β-cyclodextrin.

A new gene organization related to carbohydrate metabolism of Citrobacter species has been identified on about 4.1 kb chromosomal DNA fragment. Sequence analysis revealed four open reading frames (ORFs), and gene orders were determined to be PTS system mannitol-specific transporter subunit EIICBA (MtlA), L-sorbose-1-phosphate reductase (SorE), class II fructose-1,6-biphosphatase (GlpX), and mannitol repressor (MtlR). The deduced amino acid sequences of these ORFs showed more than 80% identities to MtlA,SorE, GlpX, and MtlR of Escherichia coli, Shigella, and Salmonella enterica, respectively. The sorE gene was heterologously expressed in E. coli. The recombinant SorE clearly showed the L-sorbose-1-phosphate reductase activity. Key words: Citrobactor sp., gene organization, carbohydrate catabolism, L-sorbose 1-phosphate reductase, gene expression.

A thermophilic Alicyclobacillus acidocaldarius, which produces thermostable α-amylase, was isolated from the hot water effluent of a boiled rice mill near Tirupati, Andhra Pradesh, India. The effect of different culture conditions on the growth and production of extracellular α-amylase by thermophilic A. acidocaldarius was investigated in laboratory scale. The results showed that the optimum conditions for the production of α-amylase are a temperature of 60°C, pH of 6.0, and medium starch concentration of 1.0%, and yeast extract and tryptone of 0.2%. Surfactants, like Tween-20 and SDS, up to 0.02%, were found to increase the bacterial growth and enzymes. Further increase in their concentration resulted in significantly decreased enzyme production.

The bacterial strain Paenibacillus xylanilyticus KJ-03 was isolated from a sample of soil used for cultivating Amorphophallus konjac. The cellulase gene, cel5A was cloned using fosmid library and expressed in Escherichia coli BL21 (trxB). The cel5A gene consists of a 1,743 bp open reading frame and encodes 581 amino acids of a protein. Cel5A contains N-terminal signal peptide, a catalytic domain of glycosyl hydrolase family 5, and DUF291 domain with unknown function. The recombinant cellulase was purified by Ni-affinity chromatography. The cellulase activity of Cel5A was detected in clear band with a molecular weight of 64 kDa by zymogram active staining. The maximum activity of the purified enzyme was displayed at a temperature of 40 °C and pH 6.0 when carboxymethyl cellulose was used as a substrate. It has 44% of its maximum activity at 70 °C and retained 66% of its original activity at 45 °C for 1 h. The purified cellulase hydrolyzed avicel, CMC, filter paper, xylan, and 4-methylumbelliferyl β-D-cellobiose, but no activity was detected against p-nitrophenyl β-D-glucoside. The end products of the hydrolysis of cellotetraose and cellopentaose by Cel5A were detected by thin layer chromatography, while enzyme did not hydrolyze cellobiose and cellotriose.

The bacteria with hydrolysis activity to glucomannan were isolated from the rhizosphere of Amorphophallus konjac through enrichment cultivation. One strain with strong activity in degrading glucomannan was identified preliminarily as Paenibacillus azotofixans YUPP-5 according to the sequence analysis of 16S rDNA. This strain is able to hydrolyze many polysaccharide with β-1,4 linkage, including glucomannan, galactomannan, xylan, carboxymethyl cellulose, and chitin. One hydrolytic enzyme band of approximately 70 kDa was examined from the supernatants of YUPP-5 by using zymogram with mixture polysaccharides as substrate. The encoding gene had an open reading frame of 2157 bp, which deduced cyclodextrin glycosyltransferase (CGTase), including 718 amino acids with a signal peptide in the N-terminal region. When the gene was expressed in Escherichia coli BL21, the recombinant CGTase exhibited strong activity in degrading polysaccharides with β-1,4 linkage, and in forming cyclodextrin by using carboxymethyl cellulose as substrate. This CGTase exhibited some new functions. Finally, the hydrolytic oligosaccharides from galactomannan or glucomannan were detected by thin layer chromatography. Pentasaccharide, tetrasaccharide, trisaccharide, and disaccharide could be examined as reaction time went on.

A gram-negative bacterium, designated strain DAU5, was isolated from shrimp shell samples because it demonstrated high β-glucosidase activity. Through 16S rDNA gene sequence analysis the strain was identified as belonging to the genus Exiguobacterium. The β-glucosidase gene of Exiguobacterium sp. DAU5 was successfully cloned by the shotgun method. Nucleotide sequence determination by sodium dodecyl sulfate-ployacrylamide gel electrophoresis indicated that the gene for the enzyme contained 1,350 bp, was coded by 450 amino acids, and was 52 kDa. The polypeptide exhibits significant homology with other bacterial β-glucosidases and belongs to the Glycoside Hydrolase Family 1. The β-glucosidase was purified by a His-fusion purification system. The optimal pH and temperature of the enzyme were 7.0 and 45°C, respectively. The enzyme activity was strongly inhibited by Ca2+, and Li+, K+, Zn2+, Mg2+, Na2+, Ni2+, and EDTA partially inhibited the enzyme activity. The BglA showed the highest activity with p-NPG and MUG. However, strain DAU5 β-glucosidase, which is for degradation of oligosaccharides, is expected to be useful for the fermentation of cellulose degradation and the transglycosylation of saccharides.

A -xylosidase encoding gene from Klebsiella sp. Sc was cloned in Escherichia coli. The -xylosidase gene consisted of an open reading frame of 1,680 nucleotides and encodes 559 amino acids with a deduced molecular weight of 63 kDa. The deduced amino acid sequence of the -xylosidase from Klebsiella sp. Sc exhibits 90% identities and 95% positives compared to those from Klebsiella oxytoca (KOX), Lactobacillus lactis (LAC, 82%, 90%), Bacillus longum (BLON, 69%, 81%) and Escherichia coli (ECOLI, 47%, 63%). The -xylosidase was purified by GST-fusion purification system. The pH and temperature optima of the enzyme were 6.6 and , respectively. The -xylosidase hydrolyzes xylobiose to xylose.

Glutaraldehyde was used to cross-link chitosan beads to immobilize the crude enzyme β-glucosidase from Exiguobacterium sp. DAU5. The conditions for preparing cross-linking chitosan beads and immobilization such as concentration of glutaradehyde, cross-linking time, immobilization pH and time were optimized. The chitosan beads were cross-linked with 1.5% glutaraldehyde for 1.5 hr. The immobilized β-glucosidase had an overall yield of 20% and specific activity of 5.22 U/g. The optimized pH and temperature were 9.0 and 55°C, respectively. More than 80% of its activity at pH 7.0-10.0, 80% at 40°C for 2 hr and 48% at 50°C for 1 hr, were retained. However, the immobilization product showed higher pH and thermal stabilities than free enzymes. It also showed high hydrolyzing activity on soybean isoflavone glycoside linkage. These results suggest the broad application prospects of immobilization enzymes.

Investigations were carried out on a β-glucosidase produced by Aspergillus niger under solid-state fermentation conditions as a model of enzyme recovery from fermented wheat bran. The leaching efficiency of distilled water to recover the enzyme from the fermented bran was higher than acetate buffer, citrate buffer, citrate-phosphate buffer and 5% methanol; thus, the conditions were further optimized with distilled water as the extracting agent. After fermented bran was washed three times with distilled water for 1.5 hr each under shaking conditions at 1:5 solid to solvent ratio, a maximum recovery of 0.025 U/g of wheat bran was obtained.

In this study, the production of extracellular thermostable α-amylase by newly isolated thermophilic Alicyclobacillus acidocaldarius was detected on LB agar plates containing 1.0% soluble potato starch and incubated at 60°C. This extracellular α-amylase was purified to homogeneity by ammonium sulphate precipitation followed by Sephadex and ion-exchange chromatography. The α-amylase was purified to 8.138 fold homogeneity with a final recovery of 58% and a specific activity of 3,239 U/mg proteins. The purified α-amylase appeared as a single protein band on SDS-PAGE with a molecular mass of 94.5 kDa. Non-denaturing PAGE analysis showed one major band associated with enzyme activity, indicating the absence of isoenzymes. A TLC analysis showed maltose as major end product of the enzyme. The optimum assay temperature and pH for enzyme activity were 60°C and 6.0 respectively; however, the enzyme activity was stable over a wide range of pH and temperatures. The α-amylase retained its activity in the presence of the denaturing agents — SDS, Triton X-100, Tween-20, Tween-80, and was significantly inhibited by EDTA and urea. Calcium ions increased the enzyme activity, while Hg2+, Zn2+, and Co2+ had inhibitory effects. The K m and V max values were found to be 2.9 mg/mL and 7936 U/mL respectively.

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/㎖. 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/㎖ with optimum conditions for incubation, yeast extract and olive oil concentrations were found to be 48 hr, 0.3 g. and 0.9 ㎖. respectively.

In this study, a potent newly-isolated glucoamylase producing actively growing cells of Bacillus sp. FME was subjected to UV irradiation and ethidium bromide (EtBr) mutagenesis. The promising colonies were further screened for glucoamylase production via plate assays and submerged enzyme production at the flask level. Amongst all of the tested colonies, the best mutant, Bacillus sp. FME 2, selected from UV irradiation (20 min) and EtBr (1 mg/mL), was shown to be the most promising. The yield of glucoamylase generated by the mutant strain was approximately 3.0 fold and 1397 U/mL with an incubation period of 24 h, which was larger than the yield generated by the wild-type strain. The glucoamylase was partially purified using ammonium sulphate precipitation followed by gel exclusion chromatography. The enzyme was partially purified 3.0-fold to homogeneity with a final recovery of 66% and a specific activity of 1145 U/mg protein for the mutant strain. The molecular mass was approximately 67.1 kDa, as determined by SDS-PAGE. The active band was observed as a clear colorless area on zymogram analysis, which indicated an absence of glucoamylase isoforms. The results of thin-layer chromatography identified this enzyme as a glucoamylase.

A recombinant plasmid, pDH3, was obtained from the genomic library of Serattia marcescens KCTC 2172, and several recombinant subclones constructed from pDH3. The nucleotide sequence of a 5,137 bp segment, pPH4, was determined and three open reading frames were detected. The three ORFs encoded the phosphate specific transport (pst) operon, which was pstC, pstA, and pstB, with the same direction of transcription. Comparison of the pst operon of S. marcescens with that of other organisms revealed that the genes for pstS and phoU were missing. A potential CRP bonding site and pho box sequence was found in the upstream of the putative promoter at the regulatory region. Analysis of the nucleotide sequence showed that homology in amino acid sequences between the PstC protein and Yersinia sp., Vibrio sp., and Pseudomonas sp. were 49, 37 and 33%, respectively. The PstA protein and Yersinia sp., Vibrio sp., and Pseudomonas sp. showed homologies of 64, 51, and 47%, respectively. PstB protein and Methanocaldococcus sp., E. coli, and Mycoplasma sp. showed homologies of 60, 50, and 48%, respectively. The pst genes could be expressed in vivo and positively regulated by cAMP-CRP. The E. coli strain harboring plasmid pPH7, with pst genes, increased with the transport of phosphate.

Acinetobacter baumannii BD5 was isolated from waters of Baek-du mountain, and the lipase gene was cloned using a PCR technique. The deduced amino acid sequence of the lipase and lipase chaperone were found to encode proteins of 325 aa and 344 aa with a molecular mass of 35 kDa and 37 kDa, respectively. The lipase gene was cloned and expressed in Escherichia coli BL21 (trxB) as an inclusion body, which was subsequently solubilized by urea, and then purified using Ni-affinity chromatography. After being purified, the lipase was refolded by incubation at 4oC in the presence of a 1:10 molar ratio of lipase:chaperone. The maximal activity of the refolded lipase was observed at a temperature of 35 degrees and pH 8.3 when p-NP caprate (C10) was used as a substrate; however, 28% of the activity observed at 35 degrees was still remaining at 0 degrees . The stability of the purified enzyme at low temperatures indicates that it is a cold-adapted enzyme. The refolded lipase was activated by Ca2+, Mg2+, and Mn2+, whereas Zn2+ and Cu2+ inhibited it. Additionally, 0.1% Tween 20 increased the lipase activity by 33%, but SDS and Triton X-100 inhibited the lipase activity by 40% and 70%, respectively.

Newly isolated strains Bacillus sp. FME 1 and FME 2 were evaluated for the cellulolytic enzymes production during submerged fermentation (SmF) of different substrates including rice husk, Whatman filter paper and cellulose powder CF 11. Extracellular enzyme assays for CMCase, FPase and β-glucosidase were examined up to 8 days of submerged fermentation. Among the three substrates, rice husk was the most suitable substrate for higher production of cellulolytic enzymes. Maximum titers of 100, 45, and 3.5 U/mL in respect of CMCase, FPase and β-glucosidase in Bacillus sp. FME 2 were recovered as against 45, 12, and 0.39 U/mL in Bacillus sp. FME 1 respectively, at their respective peak time intervals. Bacillus sp. FME 2 was found to produce higher cellulolytic enzyme activities than Bacillus sp. FME 1.

A bacterium, ZY-08 that produced extracellular mannanase, was isolated and identified as Paenibacillus illinoisensis (P. illinoisensis) on the basis of 16S rDNA phylogenetic analysis. The enzyme was purified to apparent homogeneity by ultrafiltration, DEAE-Sepharose chromatography, and Sephadex G-50 chromatography procedures. The β-mannanase was purified 3.5 fold to homogeneity with a final recovery of 22% and specificity of 9.3 U/mg protein as judged by SDS-polyacrylamide gel electrophoresis. The molecular mass was about 60 kDa. It was active at 60°C and pH 6.0 and it’s retained about 40% of activity at 70°, with a broad pH range of 3.0-6.0. The mannanase was highly specific towards glucomannan and galactomannan, but exhibited very low activity towards starch, carboxy-methyl cellulose, and birchwood xylan. Result of thin-layer chromatography analysis showed that the enzyme produced various kinds of oligosacchrides. These unique properties of the thermostable mannanase and broad substrate specificity (low activity towards cellulosic substrates) from P. illinoisensis ZY-08 make this enzyme attractive for biotechnological applications.

Hydrogen peroxide, with sodium metavanadate as the catalyst, was used to achieve a highly efficient and selective oxidation of sulfides into sulfoxides and sulfones at room temperature in high yields and short reaction times. All of the sulfides oxidized into sulfoxides and sulfone derivatives were assayed for their in vitro antibacterial activities against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa, and antifungal activities against Aspergillus niger and Candida albicans. A remarkable inhibition of the growth of the bacterial and fungal strains was observed. This result suggested that the compounds are promising microbial agents.

Bacillus thuringiensis is well known as an effective bio-insecticidal bacterium. However, the roles of B. thuringiensis to control plant diseases are not paid great attention to. In recent years, many new functions in protecting plants from pathogen infection have been discovered. For example, acyl homoserine lactone lactonase produced by B. thuringiensis can open the lactone ring of N-acyl homoserine lactone, a signal molecule in the bacterial quorum-sensing system. This in turn, significantly silences bacterial virulence. This finding resulted in the development of a new strategy against plant bacterial diseases by quenching bacterial quorum sensing. Another new discovery about B. thuringiensis function is zwittermicin A, a linear aminopolyol antibiotic with high activity against the Oomycetes and their relatives, as well as some gram-negative bacteria. This paper summarized the relative progresses of B. thuringiensis in plant disease control and its favorable application prospects.

A local isolate of Aspergillus niger was cultivated under optimal growth conditions on wheat bran in solid state fermentation. Filter paperase from fermented bran was separately extracted with different solvents to test the recovery of the enzyme. Among solvents tested, distilled water served as the best leachate, thus the conditions were further optimized with distilled water. After two washes of fermented bran with distilled water for 1.5 h each under stationary conditions at 1 g wheat bran: 5 mL distilled water, the maximum recovery of 13.5 of wheat bran was obtained.

Microbial production of cellulolytic enzymes by Aspergillus niger in solid state fermentation (SSF) and submerged state fermentation (SF) in laboratory scale was compared. Czapek Dox liquid broth amended with cellulose (0.5%) was used for cultivation in SF, whereas rice bran was used as a solid support, moistened with cellulose, amended Czapek Dox broth for growth in SSF. The production of Carboxymethyl cellulase, Filter paperase and β-Glucosidase was monitored at regular intervals. The peak production of the enzymes occurred within 3 days of incubation in SSF as against ≥ 7 days in SF. SSF gave higher yields of enzymes in comparison to SF. Maximum titres of 0.40, 0.62 and 0.013 U/ml in respect of FPase, CMCase and β-glucosidase in SSF were recovered as against 0.13, 0.06 and 0.0013 U/ml in SF respectively, at their respective peak time intervals. Hence, SSF appeared to be a better choice for production of cellulolytic enzymes by Aspergillus niger.

To get the nutritional data of hot water extract from imported kangaroo tails, research was done about contents of collagen, chondroitin sulfate, protein, fat, mineral ions, and conjugated linoleic acid (CLA) in tails. Collagen content of sulfuric acid digested sample was way higher at bones than meats in both kangaroo tail and cow tail. Comparing kangaroo tail and cow tail, meat of kangaroo tail have 1.7 times higher collagen content than that of cow tail. Content of collagen in bone parts of kangaroo tail was also higher 1.2 times than that of cow tail. Meat sample of kangaroo tail (liquid extraction) have 1.3 times higher content of muco-polysaccharide than that of cow tail. In the born part, kangaroo tail was 2.4 times higher than cow tail in its content of muco-polysaccharide. The CLA content of the kangaroo tail showed the content that was higher than 0.9% of the cow tail for 4.9% and showed about 5.3 times high ratios. Especially in kangaroo tail, a band with high content of CLA was found between C18:1 and C18:2.

Aeromonas hydrophila DA33 was isolated from cultivated soils as a bacteria having high abilities to solubilize inorganic phosphate. Glucose dehydrogenase gene (gdh) was cloned from Escherichia coli. The recombinant plasmid, pGHS containing glucose dehydrogenase gene was introduced into A. hydrophila DA33 in order to improve the activity of phosphate-solubilizing. The transformant harboring the gdh gene, A. hydrophila pGHS/DA33 increased enzyme activity. The strain also increased the gluconic acid generation that was effective for phosphate solubilization. It was possible that the strain containing pGHS produced higher solubilized phosphate with tri-calcium phosphate as the unique (P) source, in comparison with that of wild type without plasmid. These results suggest that the strain, A. hydrophila pGHS/DA33 is expected as effective biofertilizer for phosphate solubilization.

To obtain predominant bacteria degrading crude oil, we isolated some bacteria from waste soybean oil. Isolated bacterial strain had a marked tributyrin (C4:0) degrading activity as developed clear zone around the colony after incubation for 24h at 37 degrees C. It was identified as Klebsiella sp. Y6-1 by analysis of 16S rRNA gene. Crude biosurfactant was extracted from the culture supernatant of Klebsiella sp. Y6-1 by organic solvent (methanol:chloroform:1-butanol) after vacuum freeze drying and the extracted biosurfactant was purified by silica gel column chromatography. When the purified biosurfactant dropped, it formed degrading zone on crude oil plate. When a constituent element of the purified biosurfactant was analyzed by TLC and SDS-PAGE, it was composed of peptides and lipid. The emulsification activity and stability of biosurfactant was measured by using hydrocarbons and crude oil. The emulsification activity and stability of the biosurfactant showed better than the chemically synthesized surfactant. It reduced the surface tension of water from 72 to 32 mN/m at a concentration of 40 mg/l.

A mineral phosphate solubilizing bacterium, Burkholderia cepacia DA23 has been isolated from cultivated soils. Phosphate-solubilizing activities of the strain against three types of insoluble phosphate were quantitatively determined. When 3% of glucose concentration was used for carbon source, the strain had a marked mineral phosphate-solubilizing activity. Mineral phosphate solubilization was directly related to the pH drop by the strain. Analysis of the culture medium by high pressure liquid chromatography identified gluconic acid as the main organic acid released by Burkholderia cepacia DA23. Gluconic acid production was apparently the result of the glucose dehydrogenase activity and glucose dehydrogenase was affected by phosphate regulation.Uma bactéria capaz de solubilizar fosfato mineral, Burkholderia cepacea DA23, foi isolada de solo cultivado. A capacidade dessa bactéria solubilizar o fosfato de três tipos de fosfato insolúvel foi quantificada. Quando foi utilizada glicose a 3% como fonte de carbono, a bactéria apresentou uma intensa atividade solubilizante de fosfato, sendo a solubilização diretamente relacionada com a queda de pH causada pela bactéria. A análise do meio de cultura por cromatografia líquida de alta pressão indicou o ácido glicônico como principal ácido produzido por Burkholderia cepacea DA23. Aparentemente, a produção de ácido glicônico foi causada pela atividade da glicose desidrogenase. A enzima foi afetada pela regulação do fosfato.

A mineral phosphate solubilizing bacterium, Burkholderia cepacia DA23 has been isolated from cultivated soils. Phosphate-solubilizing activities of the strain against three types of insoluble phosphate were quantitatively determined. When 3% of glucose concentration was used for carbon source, the strain had a marked mineral phosphate-solubilizing activity. Mineral phosphate solubilization was directly related to the pH drop by the strain. Analysis of the culture medium by high pressure liquid chromatography identified gluconic acid as the main organic acid released by Burkholderia cepacia DA23. Gluconic acid production was apparently the result of the glucose dehydrogenase activity and glucose dehydrogenase was affected by phosphate regulation.

A microbe isolated from a soil sample obtained on Deog-yu Mountain in Korea, was found to produce an extracellular lipase. This microbe, which was designated as DYL129, was identified as an Acinetobacter sp. based on phylogenetic analysis of its 16S rDNA. A genomic library was constructed by using DYL129 fragment digested with HindIII and a recombinant plasmid, pLip-1, was selected for further analysis by colony polymerase chain reaction (PCR). Sequencing of a 3.8-kb insert in the pLip-1 clone revealed the presence of one incomplete and three complete open reading frames (ORFs). The ORFs were predicted to encode a partial lipase, two putative lipases and a 50S ribosomal protein. Genome-walking PCR also identified transcripts encoding a complete lipase chaperone and three lipaseA proteins. The lipase structural gene present in Acinetobacter sp. DYL129 was similar to the lipase structural gene found in Acinetobacter calcoaceticus BD413 (lipBA). However, the three lipase genes were located downstream of the chaperone gene in Acinetobacter sp. DYL129 (lipBA (1) A (2) A (3)), which differs from the location of these genes in A. calcoaceticus BD413. Although the amino acid sequences of these lipases (LipA(1), LipA(2), and LipA(3)) differed, both strains had a common "GHSHG" consensus motif, which is the conserved active-site pentapeptide of lipaseA. Moreover, all three lipases were found to share a conserved domain, the so-called alpha/beta hydrolase fold.

In this study, the extracellular enzyme activity ofBacillus sp. A8-8 was detected on LB agar plates containing 0.5% of the following substrates: carboxymethylcellulose (CMC), xylan, cellulose, and casein, respectively. The β-1,3-1,4 glucanase produced fromBacillus sp. A8-8 was purified by ammonium sulfate and hydrophobic chromatography. The molecular size of the protein was estimated by SDS-PAGE as approximately 33 kDa. The optimum pH and temperature for the enzyme activity were 6.0 and 60°C, respectiveley. However, enzyme activity was shown over a broad range of pH values and temperatures. The purified β-1,3-1,4 glucanase retained over 70% of its original activity after incubation at 80°C for 2 h, and showed over 40% of its original activity within the pH range of 9 to 12. This suggests that β-1,3-1,4 glucanase fromBacillus sp. A8-8 is thermostable and alkalistable. In addition, β-1,3-1,4 glucanase had higher substrate specificity to lichenan than to CMC. Finally the activity of the endoglucanase was inhibited by Fe3+, Mg2+, and Mn2+ ions. However Co2+ and Ca2+ ions were increased its activity.

Brown Ring Disease (BRD) is a bacterial disease caused by Vibrio tapetis which affects cultured clam Ruditapes philippinarum and causes heavy economic losses on Atlantic coasts of france, Spain and England. In this study, to evaluate the effective detection of the pathogen, specific primer set based on 16S ribosomal RNA (rRNA) sequences designed for rapid detection of V. tapetis. Polymerase chain reaction (PCR) with this primer set produced the specific band for each V. tapetis. The length of PCR product using designed primer set of Vbts-F and Vbts-R was about 400 bp. Therefore, these primers will be provided with a basic tool for rapid detection of V. tapetis in the various cases such as examination of imported aquatic products, diagnosis of aquatic organisms, and etc.

A bacterium producing novel lipolytic enzyme was isolated from house sewage and identified as Acinetobacter sp. BD5 based on physiological characterization and 16S rDNA sequencing. The lipolytic activity of Acinetobacter sp. BD5 was tested using an EL agar medium and CE agar medium supplemented with 1% tributyrin and olive oil, respectively. The formation of a clear zone around the colony was detected by agar medium supplemented with 1% tributyrin and olive oil, respectively and Acinetobacter sp. BD5 formed powder-like zone around the colony on LB agar medium containing Tween 20. The quantitative lipolytic activity was determined by using p-NP butyrate as substrate. Acinetobacter sp. BD5 secreted the lipolytic enzyme during exponential growth phase, reaching a maximum amount after 6 hours of incubation. The lipolytic enzyme was found to be optimally active at and retained more than 70% at . It displayed a high degree of activity in a pH of 7.0 to 10.6, with an optimal pH of 9.0.

A chitosanase-producing Bacillus sp. DAU101 was isolated from Korean traditional food. This strain was identified on the basis of phylogenetic analysis of the 16S rDNA sequence, gyrA gene, and phenotypic analysis. The gene encoding chitosanase (csn) was cloned and sequenced. The csn gene consisted of an open reading frame of 837 nucleotides and encodes 279 amino acids with a deduced molecular weight of 31,420 Da. The deduced amino acid sequence of the chitosanase from Bacillus sp. DAU101 exhibits 88 and 30 % similarity to those from Bacillus subtilis and Pseudomonas sp., respectively. The chitosanase was purified by glutathione S-transferase fusion purification system. The molecular weight of purified enzyme was about 27 kDa, which suggests the deletion of a signal peptide by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The pH and temperature optima of the enzyme were 7.5 and 50 degrees C, respectively. The enzyme activity was increased by about 1.6-fold by the addition of 5 or 10 mM Ca(2+). However, Hg(2+) and Ni(+) ions strongly inhibited the enzyme. The enzyme produced, GlcN(2-4), were the major products from a soluble chitosan.

To understand the mechanism of phosphate accumulation, a gene encoding polyphosphate kinase (PPK) was cloned from the genomic library of Serratia marcescens by Southern hybridization. From the nucleotide sequence of a 4 kb DNA fragment, an open reading frame of 2063 nucleotides was identified encoding a protein of 686 amino acids with molecular mass of 70 kDa. The potential CRP binding site and pho box sequence were found upstream of the putative promoter in the regulatory region. The expression of PPK resulted in the formation of inclusion bodies and the product was active at low temperature. The E. coli strain harboring plasmid pSPK5 with ppk gene increased enzyme activity of polyphosphate kinase, resulting in increased accumulation of polyphosphate in E. coli.