The possibility of using hyphomycete fungi as suitable biocontrol agents against greenhouse whitefly has led to the isolation of various insect pathogenic fungi. Among them is Beauveria bassiana, one of the most studied entomopathogenic fungi. The objective of this study was to use B. bassiana M130 as an insecticidal agent against the greenhouse whitefly. M130 isolated from infected insects is known to be a biocontrol agent against greenhouse whitefly. Phylogenetic classification of M130 was determined according to its morphological features and 18S rRNA sequence analysis. M130 was identified as B. bassiana M130 and showed chitinase (342.28 units/ml) and protease (461.70 units/ml) activities, which were involved in the invasion of the host through the outer cuticle layer, thus killing them. The insecticidal activity was 55.2% in petri-dish test, 84.6% in pot test, and 45.3% in field test. The results of this study indicate that B. bassiana has potential as a biological agent for the control of greenhouse whitefly to replace chemical pesticides.

Biofilm formation and antibiotic resistance are important determinants for bacterial pathogenicity. Ribonucleases control RNA degradation and there is increasing evidence that they have an important role in virulence mechanisms. In this report, we show that ribonucleases affect susceptibility against ribosome-targeting antibiotics and biofilm formation in Salmonella.

Bacillus subtilis JW-1 was isolated from rhizosphere soil as a potential biocontrol agent of bacterial wilt caused by Ralstonia solanacearum. Seed treatment followed by a soil drench application with this strain resulted in >80% reduction in bacterial wilt disease compared with that in the untreated control under greenhouse conditions. The antibacterial compound produced by strain JW-1 was purified by bioactivity-guided fractionation. Based on mass spectroscopy and nuclear magnetic resonance spectral data ($^1H$, $^{13}C$, $^1H-^1H$ correlation spectroscopies, rotating frame nuclear Overhauser effect spectroscopy, and heteronuclear multiple-bond correlation spectroscopy), the structure of this compound was elucidated as a cyclic lipopeptide composed of a heptapeptide (Gln-Leu-Leu-Val-Asp-Leu-Leu) bonded to a ${\beta}$-hydroxy-iso-hexadecanoic acid arranged in a lactone ring system.

An extracellular agarase was purified from Bacillus sp. BI-3, a thermophilic agar-degrading bacterium isolated from a hot spring in Indonesia. The purified agarase revealed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular mass of 58 kDa. The optimum pH and temperature of the agarase were 6.4 and $70^{\circ}C$, respectively. The activity of the agarase was stable at high temperatures, and more than 50% activity was retained at $80^{\circ}C$ for 15 min. Furthermore, the enzyme was stable in the pH range of 5.8-8.0, and more than 60% of the residual activity was retained. Significant activation of the agarase was observed in the presence of $K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$, and $Sr^{2+}$; on the other hand, $Ba^{2+}$, $Zn^{2+}$, $Cu^{2+}$, $Mn^{2+}$, $Co^{2+}$, $Fe^{2+}$, and EDTA inhibited or inactivated the enzyme activity. The components of the hydrolytic product analyzed by thin-layer chromatography showed that the agarase mainly produced neoagarobiose. This study is the first to present evidence of agarolytic activity in aerobic thermophilic bacteria.

Saccharothrix algeriensis NRRL B-24137 produces naturally different dithiolopyrrolone derivatives. The enzymatic activity of pyrrothine N-acyltransferase was determined to be responsible for the transfer of an acyl group from acyl-CoA to pyrrothine core. This activity was also reported to be responsible for the diversity of the dithiolopyrrolone derivatives. Based on this fact, nine dithiolopyrrolone derivatives were produced in vitro via the crude extract of Sa. algeriensis. Three of them have never been obtained before by natural fermentation: acetoacetyl-pyrrothine, hydroxybutyryl-pyrrothine, and dimethyl thiolutin (holomycin). Two acyltransferase activities, acetyltransferase and benzoyltransferase catalyzing the incorporation of linear and cyclic acyl groups to the pyrrothine core, respectively, were biochemically characterized in this crude extract. The first one is responsible for formation of acetyl-pyrrothine and the second for benzoyl-pyrrothine. Both enzymes were sensitive to temperature changes: For example, the loss of acetyltransferase and benzoyltransferase activity was 53% and 80% respectively after pre-incubation of crude extract for 60 min at $20^{\circ}C$. The two enzymes were more active in neutral and basal media (pH 7-10) than in the acidic one (pH 3-6). The optimum temperature and pH of acetyltransferase were $40^{\circ}C$ and 7, with a $K_m$ value of $7.9{\mu}M$ and a $V_{max}$ of $0.63{\mu}M/min$ when acetyl-CoA was used as limited substrate. Benzoyltransferase had a temperature and a pH optimum at $55^{\circ}C$and 9, a $K_m$ value of $14.7{\mu}M$, and a $V_{max}$ of $0.67{\mu}M/min$ when benzoyl-CoA was used as limited substrate.

Magnesium-protoporphyrin IX (Mg-PPn), which is formed through chelation of protoporphyrin IX (PPn) with Mg ion by Mg chelatase, is the first intermediate for the (bacterio)chlorophyll biosynthetic pathway. Interestingly, Mg-PPn provides peroxidase activity (approximately $4{\times}10^{-2}units/{\mu}M$) detoxifying $H_2O_2$ in the presence of electron donor(s). The peroxidase activity was not detected unless PPn was chelated with Mg ion. Mg-PPn was found freely diffusible through the membrane of Escherichia coli and Vibrio vulnificus, protecting the cells from $H_2O_2$. Furthermore, unlike photosensitizers such as tetracycline and PPn, Mg-PPn did not show any phototoxicity, but rather it protected cell from ultraviolet (UV)-A-induced stress. Thus, the exogenous Mg-PPn could be used as an antioxidant and a UV block to protect cells from $H_2O_2$ stress and UV-induced damage.

A biotransformation approach using microbes as biocatalysts can be an efficient tool for the targeted modification of existing antibiotic chemical scaffolds to create previously uncharacterized therapeutic agents. By employing a recombinant Streptomyces venezuelae strain as a microbial catalyst, a reduced macrolide, 10,11-dihydrorosamicin, was created from rosamicin macrolide. Its chemical structure was spectroscopically elucidated, and the new rosamicin analog showed 2-4-fold higher antibacterial activity against two strains of methicillin-resistant Staphylococcus aureus compared with its parent rosamicin. This kind of biocatalytic approach is able to expand existing antibiotic entities and can also provide more diverse therapeutic resources.

${\alpha}$-Neoagarooligosaccharide (${\alpha}$-NAOS) hydrolase was purified from Cellvibrio sp. OA-2007 by using chromatographic techniques after hydroxyapatite adsorption. The molecular masses of ${\alpha}$-NAOS hydrolase estimated using SDS-PAGE and gel filtration chromatography were 40 and 93 kDa, respectively, and the optimal temperature and pH for the enzyme activity were $32^{\circ}C$ and 7.0-7.2. ${\alpha}$-NAOS hydrolase lost 43% of its original activity when incubated at $35^{\circ}C$ for 30 min. The enzyme hydrolyzed neoagarobiose, neoagarotetraose, and neoagarohexaose to galactose, agarotriose, and agaropentaose, respectively, and produced 3,6-anhydro-L-galactose concomitantly; however, it did not degrade agarose.

Structurally, herboxidiene contains the tetrahydropyran acetic acid moiety and a side chain including a conjugated diene, and has been isolated from Streptomyces chromofuscus ATCC 49982. Its production was significantly elevated nearly 13.5-fold (0.74 g/l) in a medium supplemented with glycerol (medium No. 6A6), and was more efficacious (1.08 g/l; 19.8-fold) in fed-batch fermentation at 36 h in medium No. 6A6, from Streptomyces chromofuscus. For further enhancement, regulatory genes metK1-sp and afsR-sp from Streptomyces peucetius were overexpressed using an expression vector, pIBR25, and similarly ACCase from Streptomyces coelicolor and two genes, metK1-sp and afsR-sp, were also overexpressed using an integration vector, pSET152, under the control of the strong $ermE^*$ promoter in Streptomyces chromofuscus. Only the recombinant strains S. chromofuscus SIBR, S. chromofuscus GIBR, and S. chromofuscus AFS produced more herboxidiene than the parental strain in optimized medium No. 6A6 with an increment of 1.32-fold (0.976 g/l), 3.85-fold (2.849 g/l), and 1.7-fold(1.258 g/l) respectively.

One of the major challenges in metabolic engineering for enhanced synthesis of value-added chemicals is to design and develop new strains that can be translated into well-controlled fermentation processes using bioreactors. The aim of this study was to assess the influence of various fed-batch strategies in the performance of metabolically engineered Pseudomonas putida strains, ${\Delta}gcd$ and ${\Delta}gcd-pgl$, for improving production of medium-chain-length polyhydroxyalkanoates (mcl-PHAs) using glucose as the only carbon source. First we developed a fed-batch process that comprised an initial phase of biomass accumulation based on an exponential feeding carbon-limited strategy. For the mcl-PHA accumulation stage, three induction techniques were tested under nitrogen limitation. The substrate-pulse feeding was more efficient than the constant-feeding approach to promote the accumulation of the desirable product. Nonetheless, the most efficient approach for maximum PHA synthesis was the application of a dissolved-oxygen-stat feeding strategy (DO-stat), where P. putida ${\Delta}gcd$ mutant strain showed a final PHA content and specific PHA productivity of 67% and $0.83g{\cdot}l^{-1}{\cdot}h^{-1}$, respectively. To our knowledge, this mcl-PHA titer is the highest value that has been ever reported using glucose as the sole carbon and energy source. Our results also highlighted the effect of different fed-batch strategies upon the extent of realization of the intended metabolic modification of the mutant strains.

In an attempt to develop a variety of expression vector systems for Corynebacterium glutamicum, six types of promoters, including $P_{tac}$, $P_{sod}$, $P_{sod}$ with a conserved Shine-Dalgarno (SD) sequence from C. glutamicum, $P_{ilvC}$, $P_{ilvC}$ with a conserved SD-1 ($P_{ilvC-M1}$), and $P_{ilvC}$ with a conserved SD-2 ($P_{ilvC-M2}$), were cloned into a modified shuttle vector, pCXM48. According to analysis of promoter strength by quantitative reverse transcription PCR, $P_{sod}$ and $P_{sod-M}$ were superior to tac and ilvC promoters in terms of transcription activity in C. glutamicum. All of the promoters have promoter activities in Escherichia coli, and $P_{sod-M}$ displayed the highest level of transcriptional activity. The protein expression in constructed vectors was evaluated by measuring the fluorescence of green fluorescent protein (GFP) and SDS-PAGE. C. glutamicum harboring plasmids showed GFP fluorescence with an order of activity of $P_{ilvC}$ > $P_{ilvC-M1}$ > $P_{sod}$ > $P_{ilvC-M2}$ > $P_{sod-M}$, whereas all plasmids except pCSP30 with $P_{sod}$ displayed fluorescence activities in E. coli. Of them, the strongest level of GFP was observed in E. coli with $P_{sod-M}$, and this seems to be due to the introduction of the conserved SD sequence in the translational initiation region. These results demonstrate that the expression vectors work well in both C. glutamicum and E. coli for the expression of target proteins. In addition, the vector systems harboring various promoters with different strengths, conserved SD sequences, and multiple cloning sites will provide a comfortable method for cloning and gene expression, and consequently contribute to the metabolic engineering of C. glutamicum.

Tannase (Tan410) from a soil metagenomic library was immobilized on different supports, including mesoporous silica SBA-15, chitosan, calcium alginate, and amberlite IRC 50. Entrapment in calcium alginate beads was comparatively found to be the best method and was further characterized. The optimum pH of the immobilized Tan410 was shifted toward neutrality compared with the free enzyme (from pH 6.4 to pH 7.0). The optimum temperature was determined to be $45^{\circ}C$ for the immobilized enzyme and $30^{\circ}C$ for the free enzyme, respectively. The immobilized enzyme had no loss of activity after 10 cycles, and retained more than 90% of its original activity after storage for 30 days. After immobilization, the enzyme activity was only slightly affected by $Hg^{2+}$, which completely inhibited the activity of the free enzyme. The immobilized tannase was used to remove 80% of tannins from a green tea infusion on the first treatment. The beads were used for six successive runs resulting in overall hydrolysis of 56% of the tannins.

In the present study, a yeast species isolated from CETP, Vellore, Tamilnadu was identified as Cryptococcus sp. VITGBN2 based on molecular techniques and was found to be a potent producer of acidic diacetate sophorolipid in mineral salt media containing vegetable oil as additional carbon source. The chemical structure of the purified biosurfactant was identified as acidic diacetate sophorolipid through GC-MS analysis. This sophorolipid was used as a stabilizer for synthesis of zinc oxide nanoparticles (ZON). The formation of biofunctionalized ZON was characterized using UV-visible spectroscopy, XRD, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy. The antimicrobial activities of naked ZON and sophorolipid functionalized ZON were tested based on the diameter of inhibition zone in agar well diffusion assay, microbial growth rate determination, protein leakage analysis, and lactate dehydrogenase assay. Bacterial pathogen Salmonella enterica and fungal pathogen Candida albicans showed more sensitivity to sophorolipid biofunctionalized ZON compared with naked ZON. Among the two pathogens, S. enterica showed higher sensitivity towards sophorolipid biofunctionalized ZON. SEM analysis showed that cell damage occurred through cell elongation in the case of S. enterica, whereas cell rupture was found to occur predominantly in the case of C. albicans. This is the first report on the dual role of yeast-mediated sophorolipid used as a biostabilizer for ZON synthesis as well as a novel functionalizing agent showing antimicrobial property.

Quorum quenching (QQ) with a microbial vessel has recently been reported as an economically feasible biofouling control platform in a membrane bioreactor (MBR) for wastewater treatment. In this study, a quorum quenching MBR with a ceramic microbial vessel (CMV) was designed to overcome the extremely low F/M ratio inside a microbial vessel. The CMV was prepared with a monolithic ceramic microporous membrane and AHL-degrading QQ bacteria, Pseudomonas sp. 1A1. The "inner flow feeding mode" was introduced, under which fresh feed was supplied to the MBR only through the center lumen in the CMV. The inner flow feeding mode facilitated nutrient transport to QQ bacteria in the CMV and thus enabled relatively long-term maintenance of cell viability. The quorum quenching effect of the CMV on controlling membrane biofouling in the MBR was more pronounced with the inner flow feeding mode, which was identified by the slower increase in the transmembrane pressure as well as by the visual observation of a biocake that formed on the used membrane surface. In the QQ MBR with the CMV, the concentrations of extracellular polymeric substances were substantially decreased in the biocake on the membrane surface compared with those in the conventional MBR. The CMV also showed its potential with effective biofouling control over long-term operation of the QQ MBR.

Very few plant growth-promoting rhizobacteria (PGPR) are known to produce gibberellins (GAs). The current study aimed to isolate a phytohormone-producing PGP rhizobacterium from soil and assess its potential to enhance plant growth. The newly isolated bacterium was identified as Leifsonia soli sp. SE134 on the basis of partial 16S ribosomal RNA gene sequence. Application of L. soli culture filtrate significantly increased the biomass, hypocotyl, and root lengths of cucumber seeds as compared with non-inoculated sole medium and distilled water treated controls. Furthermore, the PGPR culture was applied to the GA-deficient mutant rice cultivar Waito-C. Treatment with L. soli SE134 significantly increased the growth of Waito-C rice seedlings as compared with controls. Upon chromatographic analysis of L. soli culture, we isolated, detected and quantified different GAs; namely, $GA_1$ ($0.61{\pm}0.15$), $GA_4$ ($1.58{\pm}0.26$), $GA_7$ ($0.54{\pm}0.18$), $GA_8$ ($0.98{\pm}0.15$), $GA_9$ ($0.45{\pm}0.17$), $GA_{12}$ ($0.64{\pm}0.21$), $GA_{19}$ ($0.18{\pm}0.09$), $GA_{20}$ ($0.78{\pm}0.15$), $GA_{24}$ ($0.38{\pm}0.09$), $GA_{34}$ ($0.35{\pm}0.10$), and $GA_{53}$ ($0.17{\pm}0.05$). Plant growth promotion in cucumber, tomato, and young radish plants further evidenced the potential of this strain as a PGP bacterium. The results suggest that GA secretion by L. soli SE134 might prove advantageous for its ameliorative role in crop growth. These findings can be extended for improving the productivity of different crops under diverse environmental conditions.

Environmental microorganisms are emerging as an important source of new enzymes for wide-scale industrial application. In this study, novel phytase genes were identified from a soil microbial community. For this, a function-based screening approach was utilized for the identification of phytase activity in a metagenomic library derived from an agricultural soil. Two novel phytases were identified. Interestingly, one of these phytases is an unusual histidine acid phosphatase family phytase, as the conserved motif of the active site of PhyX possesses an additional amino acid residue. The second phytase belongs to a new type, which is encoded by multiple open reading frames (ORFs) and is different to all phytases known to date, which are encoded by a single ORF.

Rheumatoid arthritis (RA) is a chronic and systemic inflammatory disorder that primarily affects the flexible joints and may also affect a number of tissues and organs. The progression of RA involves an inflammatory response of the capsule around the joint, swelling of synovial cells with excess synovial fluid (SF), and the development of fibrous tissue in the synovium. Since the progressive pathology of the disease often leads to the irreversible destruction of articular cartilage and ankylosis of the joint, early diagnosis of RA is essential. Thus, we undertook a comparative proteomic approach to investigate novel biomarkers for early diagnosis using SFs and serums from RA patients. As a result, we identified 32 differentially expressed spots in SFs and 34 spots in serums. The differential expression of the STEAP4 and ZNF 658 proteins were validated using immunoblotting of the SFs and serums, respectively. These data suggest that differentially expressed proteins in SFs and serums could be used as RA-specific biomarkers for the diagnosis and monitoring of RA. Furthermore, these findings advance our understanding of the molecular etiopathogenesis of RA.

While searching for lactic acid bacteria that can restore aging-impaired immune responses, we isolated the Toll-like receptor (TLR) 2/NF-${\kappa}B$-activating strain Lactobacillus plantarum HY7712 from kimchi and investigated its immunomodulating effect in whole-body ${\gamma}$-irradiated mice. Exposure to HY7712 strongly activated NF-${\kappa}B$ signaling in RAW264.7 cells, but inhibited lipopolysaccharide-stimulated NF-${\kappa}B$ activation. Moreover, HY7712 protected against the downregulation of interferon (IFN)-${\gamma}$ and upregulation of interleukin (IL)-13 caused by ${\gamma}$-irradiation in mice. In mice, ${\gamma}$-irradiation impaired NK-cell activity against YAC-1 tumor cells, but following HY7712 exposure, the activity of NK cells was restored to 91.5% of the level measured in control mice (p < 0.05). These findings suggest that HY7712 activates the TLR2/NF-${\kappa}B$ signaling pathway and protects against the impairment of NK-cell activity caused by ${\gamma}$-irradiation or aging.