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Effects of actinobacteria on plant disease suppression and growth promotion
Palaniyandi, Sasikumar Arunachalam,Yang, Seung Hwan,Zhang, Lixin,Suh, Joo-Won Springer-Verlag 2013 Applied microbiology and biotechnology Vol.97 No.22
<P>Biological control and plant growth promotion by plant beneficial microbes has been viewed as an alternative to the use of chemical pesticides and fertilizers. Bacteria and fungi that are naturally associated with plants and have a beneficial effect on plant growth by the alleviation of biotic and abiotic stresses were isolated and developed into biocontrol (BCA) and plant growth-promoting agents (PGPA). Actinobacteria are a group of important plant-associated spore-forming bacteria, which have been studied for their biocontrol, plant growth promotion, and interaction with plants. This review summarizes the effects of actinobacteria as BCA, PGPA, and its beneficial associations with plants.</P>
( Sasikumar Arunachalam Palaniyandi ),( Seung Hwan Yang ),( Joo Won Suh ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6
Yam anthracnose caused by Colletotrichum gloeosporioides (C.g) is the most devastating disease of yam (Dioscorea sp.). In the present study, we evaluated the culture filtrate extract (CFE) of azalomycin-producing Streptomyces malaysiensis strain MJM1968 for the control of yam anthracnose. MJM1968 showed strong antagonistic activity against C.g in vitro. Furthermore, the MJM1968 CFE was tested for inhibition of spore germination in C.g, where it completely inhibited spore germination at a concentration of 50 μg/ml. To assess the in planta efficacy of the CFE and spores of MJM1968 against C.g, a detached leaf bioassay was conducted, which showed both the treatments suppressed anthracnose development on detached yam leaves. Furthermore, a greenhouse study was conducted to evaluate the CFE from MJM1968 as a fungicide for the control of yam anthracnose. The CFE non-treated plants showed a disease severity of >92% after 90 days of artificial inoculation with C.g, whereas the disease severity of CFE-treated and benomyl-treated yam plants was reduced to 26% and 15%, respectively, after 90 days. Analysis of the yam tubers from the CFE-treated and non-treated groups showed that tubers from the CFE-treated plants were larger than that of non-treated plants, which produced abnormal smaller tubers typical of anthracnose. This study demonstrated the utility of the CFE from S. malaysiensis strain MJM1968 as a biofungicide for the control of yam anthracnose.
Sasikumar Arunachalam Palaniyandi,손병모,Karthiyaini Damodharan,서주원,양승환 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.5
Lactic acid bacteria (LAB) were screened for ginsenoside transforming activity using crude ginseng extract. Thin-layer chromatography analysis of fermented ginseng extract showed that LAB strain MJM60396 possessed higher ginsenoside transformation ability than other strains. It converted major ginsenosides into minor ginsenosides such as Rg3 and Rh2. MJM60396 also showed high β-glucosidase activity. Strain MJM60396 was identified as Lactobacillus paracasei subsp. tolerans based on 16S rRNA gene sequence. To delineate the pathway involved in the production of the minor ginsenosides Rg3 and Rh2, strain MJM60396 was incubated with pure ginsenoside Rb1. HPLC analysis revealed the appearance of Rg3 and Rh2 peak from the incubation mixture containing Rb1 and strain MJM60396. Furthermore, β-glucosidase enzyme was prepared from strain MJM60396. To achieve its maximum activity, we optimized the pH and temperature conditions. Cell-free β-glucosidase enzyme hydrolyzed ginsenoside Rb1 through the following pathway: ginsenoside Rb1 → Rd → Rg3 → Rh2. This is the first report on the transformation of ginsenosides Rb1 to Rg3 and Rh2 by a Lac. paracasei subsp. tolerans strain. Our results indicate that Lac. paracasei subsp. tolerans MJM60396 has the potential to be used for preparing ginsenosides Rg3 and Rh2 as nutraceuticals.
Palaniyandi, Sasikumar Arunachalam,Suh, Joo-Won,Yang, Seung Hwan Medknow PublicationsMedia Pvt Ltd 2017 Pharmacognosy magazine Vol.13 No.49
<P><B>Background:</B></P><P>Ginsenosides are the principal components responsible for the pharmacological activities of ginseng. Ginsenosides Rg1 and Rb1 are the major compounds recognized as marker substances for quality control of ginseng-based products. These major compounds can be transformed to several pharmacologically active minor ginsenosides by chemical, microbial, and enzymatic means.</P><P><B>Materials and Methods:</B></P><P>In the present study, a combination of polysaccharide hydrolases and high hydrostatic pressure (HHP) were used to extract ginseng saponins enriched with ginsenosides Rg1 and Rb1. Temperature, pH, time, ginseng-to-water ratio, and pressure were optimized to obtain the maximum amount of Rg1 and Rb1 in the resulting extract using commercial polysaccharide hydrolases.</P><P><B>Results:</B></P><P>This study showed that treatment with a combination of cellulase, amylase, and pectinase at 100 MPa pressure, pH 4.8, and 45°C for 12 h resulted in higher Rg1 and Rb1 levels in the extract.</P><P><B>Conclusion:</B></P><P>This study describes a cheap and ecofriendly method for preparing ginseng extract enriched with Rg1 and Rb1.</P><P><B>SUMMARY</B></P><P><P>Ginsenosides are the principal bioactive components present in ginseng</P><P>Ginsenosides Rg1 and Rb1 are the most abundant compounds in ginseng</P><P>High hydrostatic pressure (HHP) and Polysaccharide hydrolases (PH) were combined to extract ginseng saponins enriched with Rg1 and Rb1</P><P>Extraction conditions were optimized to obtain the maximum amount of Rg1 and Rb1</P><P>Extraction with a combination of cellulase, amylase, and pectinase at 100 MPa pressure at pH 4.8, and 45°C for 12 h resulted in higher levels of Rg1 and Rb1 in the ginseng extract</P></P> >[FIG OMISSION]</BR><P><B>Abbreviations used:</B> ATCC: American Type Culture Collection, Mpa: Mega Pascal</P>
( Sasikumar Arunachalam Palaniyandi ),( Karthiyaini Damodharan ),( Joo-won Suh ),( Seung Hwan Yang ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.5
The present study focused on the production, characterization, and in vitro prebiotic evaluation of an exopolysaccharides (EPS) from Bacillus sonorensis MJM60135 isolated from ganjang (fermented soy sauce). Strain MJM60135 showed the highest production (8.4 ± 0.8 g/l) of EPSs compared with other isolates that were screened for EPS production based on ropy culture morphology. Furthermore, MJM60135 was cultured in 5 L of medium and the EPS was extracted by ethanol precipitation. The emulsification activity of the EPS was higher in toluene than in o-xylene. Fourier transform infrared spectroscopy analysis showed the presence of hydroxyl and carboxyl groups and glycosidic linkages. The isolated EPS contained mannose and glucose, as observed by thin-layer chromatography analysis of the EPS hydrolysate. Lactic acid bacteria (LAB) and pathogenic E. coli K99 and Salmonella enterica serovar Typhimurium were tested for their growth utilizing the EPS from B. sonorensis MJM60135 as the sole carbon source for its possible use as a prebiotic. All the tested LAB exhibited growth in the EPSsupplied medium compared with glucose as carbon source, whereas the pathogenic strains did not grow in the EPS-supplied medium. These findings indicate that the EPS from B. sonorensis MJM60135 has potential application in the bioremediation of hydrocarbons and could also be used as a prebiotic.
Sasikumar Arunachalam Palaniyandi,Bao Le,김진만,양승환 한국미생물학회 2018 미생물학회지 Vol.54 No.4
Ginseng are native traditional herbs, which exhibit excellentpharmacological activities. Probiotic Lactobacillus helveticusKII13 and Pediococcus pentosaceus strain KID7 were used forginsenoside transformation by fermenting crude ginseng extractto enhance minor gisenoside content. Thin-layer chromatography(TLC) analysis of fermented ginseng extract showed that theminor ginsenosides Rg3, Rh1, and Rh2 were main productsafter 5 days of fermentation. HPLC analysis was performed toquantify the major and minor ginsenosides. The Rg3 peakappeared on the 3rd day while the appearance of Rh2 peak andRh1 peak were observed on the 5th day. The co-culture of L. helveticus KII13 and P. pentosaceus KID7 converted majorginsenosides (Rb1 and Rg1) into minor ginsenosides (Rg3,Rh2, and Rh1).
Karthiyaini Damodharan,Sasikumar Arunachalam Palaniyandi,양승환,서주원 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.3
The aim of this study was to enhance the viability of probiotic strains Pediococcus pentosaceus KID7, Lactobacillus plantarum KII2, Lactobacillus fermentum KLAB6 and Lactobacillus helveticus KII13 in gastrointestinal transit, freeze-drying condition and during storage time by microencapsulation using a combination of alginate, fenugreek gum and locust bean gum. The microcapsules were prepared using various ratio of alginate to fenugreek gum to locust bean gum and tested for its dissolution in colonic fluid. The combination that efficiently dissolved in colonic fluid was selected for co-encapsulation of the probiotic strains and prebiotics to produce synbiotic microcapsules. Further, we observed that the bacteria encapsulated with alginate-fenugreek gum-locust bean gum (AFL) matrix tolerated gastrointestinal condition efficiently compared to non-encapsulated bacteria. The encapsulated bacterial cells retained higher viability than non-encapsulated cells during freeze-drying condition and subsequent storage for 3 months at 4°C. These results show the utility of AFL matrix in microencapsulation of probiotics for use in food industry.
( Karthiyaini Damodharan ),( Sasikumar Arunachalam Palaniyandi ),( Seung Hwan Yang ),( Joo Won Suh ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.10
We characterized the probiotic properties of Lactobacillus helveticus strains KII13 and KHI1 isolated from fermented cow milk by in vitro and in vivo studies. The strains exhibited tolerance to simulated orogastrointestinal condition, adherence to Caco-2 cells, and antimicrobial activity. Both L. helveticus strains produced bioactive tripeptides, isoleucylprolyl- proline and valyl-prolyl-proline, during fermentation of milk. KII13 showed higher in vitro cholesterol-lowering activity (47%) compared with KHI1 (28%) and L. helveticus ATCC 15009 (22%), and hence, it was selected for in vivo study of cholesterol-lowering activity in atherogenic diet-fed hypercholesterolemic mice. For the study, mice were divided into four groups (viz., normal diet control group, atherogenic diet control group (HCD), KII13- atherogenic diet group (HCD-KII13), and Lactobacillus acidophilus ATCC 43121-atherogenic diet group (HCD-L.ac) as positive control). The serum total cholesterol level was significantly decreased by 8.6% and 7.78% in the HCD-KII13 and HCD-L.ac groups (p < 0.05), respectively, compared with the HCD group. Low-density lipoprotein cholesterol levels in both HCD-KII13 and HCD-L.ac groups were decreased by 13% and 11%, respectively, compared with the HCD group (both, p < 0.05). Analysis of cholesterol metabolism-related gene expression in mice liver showed increased expression of LDLR and SREBF2 genes in mice fed with KII13. By comparing all the results, we conclude that L. helveticus KII13 could be used as a potential probiotic strain to produce antihypertensive peptides and reduce serum cholesterol.
Karthiyaini Damodharan,Sasikumar Arunachalam Palaniyandi,Bao Le,서주원,양승환 한국미생물학회 2018 The journal of microbiology Vol.56 No.10
A novel actinobacterium, strain SK68, was isolated from the rhizosphere of peanut plant and its salinity stress alleviation ability was studied using tomato (Solanum lycopersicum cv. Micro-Tom) plants. Based on 16S rDNA based phylogenetic analysis, strain SK68 has been identified as a Streptomyces sp. Strain SK68 had branched substrate mycelium bearing smooth surfaced spores and the spore colour is brownish grey on ISP4 medium. It exhibited enzyme activities such as xylanase, cellulase, amylase, and pectinase and degraded hypoxanthine, casein, and L-tyrosine. The strain SK68 differed in its banding pattern in BOX-PCR and RAPD fingerprinting compared to the closely matching type strains Streptomyces erythrochromogenes NBRC 3304T (AB184746), S. flavotricini NBRC 12770T (AB184132), S. racemochromogenes NBRC 12906T (AB184235), and S. polychromogenes NBRC 13072T (NR041109). Strain SK68 was evaluated for its salinity stress-alleviating activity in tomato plants with 180 mmol/L NaCl under gnotobiotic condition. A significant increase in plant biomass was observed in strain SK68-inoculated tomato plants under salt stress compared to control and salt-stressed non-inoculated plants.