Bioprospecting medicinal plants for the isolation and screening of lovastatin producing endophytic fungi

46-51Endophytic fungi reside within the plant tissues asymptomatically and produce various secondary metabolites of pharmaceutical interest. The current study aims to bio-prospect medicinal plants for the isolation and screening of lovastatin producing endophytic fungi. Endophytic population in the leaf, stem, root and flower (as applicable) of ten medicinal plants has been studied and their potential to produce the anti-hypercholesterolemia drug, lovastatin has been evaluated. A total of 98 fungal isolates were obtained from the plant tissues and lovastatin yield from them was quantified to be within the range of 5 mg/L to 71.5 mg/L in the first round of submerged fermentation. The subsequent levels of screening witnessed a great change in the yield which could be attributed to gene attenuation, a usual phenomenon in endophytes. A novel lovastatin producer, designated as HL1, belonging to candida sp. residing within the leaves of Hibiscus rosa-sinensis was found to consistently yield higher amounts of lovastatin i.e., 40 mg/L through all rounds of screening, alongside two strains of Aspergillus sp., designated as HL4 and HL5, from the same tissue with a yield of 21.5 and 18 mg/L respectively. Preliminary confirmation of lovastatin presence in the fungal extract was done by Thin Layer Chromatography (TLC) and yeast growth inhibition bioassay

Bioprospecting medicinal plants for the isolation and screening of lovastatin producing endophytic fungi

Endophytic fungi reside within the plant tissues asymptomatically and produce various secondary metabolites of pharmaceutical interest. The current study aims to bio-prospect medicinal plants for the isolation and screening of lovastatin producing endophytic fungi. Endophytic population in the leaf, stem, root and flower (as applicable) of ten medicinal plants has been studied and their potential to produce the anti-hypercholesterolemia drug, lovastatin has been evaluated. A total of 98 fungal isolates were obtained from the plant tissues and lovastatin yield from them was quantified to be within the range of 5 mg/L to 71.5 mg/L in the first round of submerged fermentation. The subsequent levels of screening witnessed a great change in the yield which could be attributed to gene attenuation, a usual phenomenon in endophytes. A novel lovastatin producer, designated as HL1, belonging to candida sp. residing within the leaves of Hibiscus rosa-sinensis was found to consistently yield higher amounts of lovastatin i.e., 40 mg/L through all rounds of screening, alongside two strains of Aspergillus sp., designated as HL4 and HL5, from the same tissue with a yield of 21.5 and 18 mg/L respectively. Preliminary confirmation of lovastatin presence in the fungal extract was done by Thin Layer Chromatography (TLC) and yeast growth inhibition bioassay

Poly- β

Fusarium solani Thom produced maximum PHB depolymerase by 48 h when grown in BHM containing 0.2%, w/v PHB, pH 8.0 at 25°C. Statistical optimization studies using Plackett Burman design of PHB depolymerase production yielded maximum PHB depolymerase activity after 2 days as against 4 days in the unoptimized conditions with a 2-fold increase in activity. Partial purification of the extracellular poly-β-hydroxybutyrate (PHB) depolymerase PHAZFus from F. solani Thom by two steps using ammonium sulphate (80% saturation) and affinity chromatography using concanavalin-A yielded 162.3-fold purity and 63% recovery of protein. The enzyme composed of a single polypeptide chain of 85 KDa, as determined by SDS-PAGE. The enzyme stained positive for glycoprotein by PAS staining. Optimum enzyme activity was detected at pH 7.0 and 55°C. The enzyme was stable at pH 7.0 and 55°C for 24 h with a residual activity of almost 85%. Paper chromatography revealed β-hydroxybutyrate monomer as the major end product of PHB hydrolysis. Complete inhibition of the enzyme by 1 mM HgCl2 (100%) indicated the importance of essential disulfide bonds (cystine residues) for enzyme activity or probably for maintaining the native enzyme structure

Agrowaste-based Polyhydroxyalkanoate (PHA) production using hydrolytic potential of Bacillus thuringiensis IAM 12077

The study identified the innate enzymatic potential (amylase) of the PHB producing strain B.thuringiensis IAM 12077 and explored the same for cost-effective production of PHB using agrowastes, eliminating the need for pretreatment (acid hydrolysis and/or commercial enzyme). Comparative polyhydroxyalkanoate (PHA) production by B. thuringiensis IAM 12077 in biphasic growth conditions using glucose and starch showed appreciable levels of growth (5.7 and 6.8 g/L) and PHA production (58.5 and 41.5%) with a PHA yield of 3.3 and 2.8 g/L, respectively. Nitrogen deficiency supported maximum PHA yield (2.46 g/L) and accumulation (53.3%). Maximum growth (3.6 g/L), PHB yield (2.6 g/L) and PHA accumulation (72.8%) was obtained with C:N ratio of 8:1 using starch as the carbon source (10 g/L). Nine substrates (agro and food wastes) viz. rice husk, wheat bran, ragi husk, jowar husk, jackfruit seed powder, mango peel, potato peel, bagasse and straw were subjected to two treatments- acid hydrolysis and hydrolysis by innate enzymes, and the reducing sugars released thereby were utilized for polymer production. All the substrates tested supported comparable PHB production with acid hydrolysis (0.96 g/L-8.03 g/L) and enzyme hydrolysis (0.96 g/L -5.16 g/L). Mango peel yielded the highest PHB (4.03 g/L; 51.3%), followed by jackfruit seed powder (3.93 g/L; 29.32%). Varied levels of amylase activity (0.25U-10U) in all the substrates suggested the enzymatic hydrolysis of agrowastes

Optimization of mycolytic enzymes (Chitinase, <span style="font-size:15.0pt;font-family:Symbol;mso-bidi-font-family:Symbol"><img src='/image/spc_char/beta.gif' border=0>1,3-Glucanase and <span style="font-size:15.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-ansi-language:EN-IN;mso-fareast-language:EN-IN; mso-bidi-language:AR-SA">Cellulase) production by <i>Bacillus subtilis</i>, a potential biocontrol agent using one-factor approach</span></span>

172-178This study presents one-factor approach for optimization of growth and physical parameters for increasing production of three mycolytic enzymes viz. chitinase, <span style="font-size: 9.0pt;font-family:Symbol;mso-bidi-font-family:Symbol">-1,3-glucanase and <span style="font-size:9.0pt; font-family:Symbol;mso-bidi-font-family:Symbol">1,4-glucanase (cellulase) by B.subtilis, a potent biocontrol agent. Maximum enzyme activity of all three enzymes was observed in the following physical parameters: pH 7.0, temperature of 30°C, and incubation period of 72h. Optimum nutritional parameters were found to be as follows: Carboxymethyl cellulose (CMC, 10g/L); Corn steep liquor (CSL, 1g/L) or KNO3 (1 g/L), CaCl2 (5mM)and Triton X 100 (0.1% v/v). Using one factor approach, production of all three enzymes ignificantly increased for chitinase (5.49 folds); â-1,3-glucanase (7.39 folds) and cellulase (1.91 folds) respectively as compared to the un-optimized media containing Nutrient broth. The crude mycolytic enzymes had activity in acidic pH (4 - 6) and temperature (50 - 60°C) range with optima at pH 6.0 and 55°C, respectively. However, chitinase showed two pH optima at pH 6 and 11 indicating the possibility of having two isoforms. The enzymes showed varied response to metal ions. Identification of essential nutrients affecting co-production of three enzymes by a single strain would help to formulate a suitable medium for their concerted production. Moreover, low cost cellulosic materials can be used as carbon source for these enzymes production by the isolate for industrial and agricultural applications. </span

Prevalence and risk factors for adult pulmonary tuberculosis in a metropolitan city of South India.

The present study measured the community prevalence and risk factors of adult pulmonary tuberculosis (PTB) in Chennai city, and also studied geographical distribution and the presence of different M. tuberculosis strains in the survey area.A community-based cross sectional survey was carried out from July 2010 to October 2012 in Chennai city. Prevalence of bacteriologically positive PTB was estimated by direct standardization method. Univariate and multivariate analyses were carried out to identify significant risk factors. Drug susceptibility testing and spoligotyping was performed on isolated M. tuberculosis strains. Mapping of PTB cases was done using geographic positioning systems.Of 59,957 eligible people, 55,617 were screened by X-ray and /or TB symptoms and the prevalence of smear, culture, and bacteriologically positive PTB was estimated to be 228 (95% CI 189-265), 259 (95% CI 217-299) and 349 (95% CI 330-428) per 100,000 population, respectively. Prevalence of smear, culture, and bacteriologically positive PTB was highest amongst men aged 55-64 years. Multivariate analysis showed that occurrence of both culture and bacteriologically positive PTB disease was significantly associated with: age >35 years, past history of TB treatment, BMI <18.5 Kgs/m2, solid cooking fuel, and being a male currently consuming alcohol. The most frequent spoligotype family was East African Indian. Spatial distribution showed that a high proportion of patients were clustered in the densely populated north eastern part of the city.Our findings demonstrate that TB is a major public health problem in this urban area of south India, and support the use of intensified case finding in high risk groups. Undernutrition, slum dwelling, indoor air pollution and alcohol intake are modifiable risk factors for TB disease

Univariate analysis of factors associated with the occurrence of bacteriologically (Bact) positive and culture (Cult) positive PTB.

<p>*a p-value of <0.05 was considered significant;</p><p>#: Bact = Bacteriologically,</p><p>Cult = Culture</p><p>Univariate analysis of factors associated with the occurrence of bacteriologically (Bact) positive and culture (Cult) positive PTB.</p

Age and sex wise prevalence of smear positive pulmonary TB.

<p>Age and sex wise prevalence of smear positive pulmonary TB.</p