Production of Biodegradable Polymer from Agro-Wastes in Alcaligenes sp. and Pseudomonas sp.

The present study was aimed to evaluate the suitability of agro-wastes and crude vegetable oils for the cost-effective production of poly-ß-hydroxybutyrate (PHB), to evaluate growth kinetics and PHB production in Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1 with these carbon substrates and to study the biodegradation of PHB accumulated by these cultures. Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1 accumulates higher amounts of PHB corn (79.90% of dry cell mass) and rice straw (66.22% of dry cell mass) medium respectively. The kinetic model suggests that the Pseudomonas sp. RZS1 follows the Monod model more closely than A. faecalis RZS4. Both the cultures degrade their PHB extract under the influence of PHB depolymerase. Corn waste and rice straw appear as the best and cost-effective substrates for the sustainable production of PHB from Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1. The biopolymer accumulated by these organisms is biodegradable in nature. The agro-wastes and crude vegetable oils are good and low-cost sources of nutrients for the growth and production of PHB and other metabolites. Their use would lower the production cost of PHB and the low-cost production will reduce the sailing price of PHB-based products. This would promote the large-scale commercialization and popularization of PHB as an ecofriendly bioplastic/biopolymer.

Dynamism of PGPR in bioremediation and plant growth promotion in heavy metal contaminated soil.

Heavy metal contamination, particularly of cultivable lands, is a matter of concern. Bioremediation helps in reversing such contamination to certain extent. Here, we report isolation, polyphasic identification and the role of siderophore producing rhizobacteria Alcaligenes feacalis RZS2 and Pseudomonas aeruginosa RZS3 in bioremediation of heavy metal contaminated soil and plant growth promotion activity in such contaminated soil. Siderophore produced by A. feacalis RZS2 and P. aeruginosa RZS3 strains chelated various heavy metal ions like MnCl2.4H2O, NiCl2.6H2O, ZnCl2, CuCl2 and CoCl2 other than FeCl3.6H2O at batch scale. Their bioremediation potential was superior over the chemical ion chelators like EDTA and citric acid. These isolates also promoted growth of wheat and peanut seeds sown in heavy metal contaminated soil. Effective root colonizing ability of these isolates was observed in wheat and peanut plants.

Statistical-based optimization and scale-up of siderophore production process on laboratory bioreactor.

We report the enhanced production of siderophore in succinate medium by applying two-stage statistical approach, i.e., Plackett-Burman design and response surface methodology (RSM) using central composite design (CCD). In the first stage of optimization, out of 11 variable components of succinate medium, succinic acid, pH and temperature were found as significant components that influenced the siderophore production in Pseudomonas aeruginosa RZS9. The second stage of RSM using CCD consisted of optimizing the concentrations of the variables. Here, 0.49 g/100 ml concentration of succinic acid, pH 7.08 and temperature of 27.80 °C yielded the maximum (68.41 %) siderophore units. All the significant components exhibited quadratic effect on siderophore production. The F value of 28.63, multiple correlation coefficient (R 2) of 0.9626, percent coefficient of variation of 8.81 values indicated that the model was significant and that the experimental data was satisfactorily adjusted to the quadratic model. During validation of these experiments, 6.10 % increase in siderophore yield was obtained. Scale-up of this protocol optimized at shake  flask level up to 5 L-capacity reactor further enhanced the siderophore yield. We claim it to be the first report on statistical optimization of siderophore production by P. aeruginosa RZS9.

Stenotrophomonas sp. RZS 7, a novel PHB degrader isolated from plastic contaminated soil in Shahada, Maharashtra, Western India.

This paper reports an isolation and identification of novel poly-ß-hydroxybutyrate (PHB) degrading bacterium Stenotrophomonas sp. RZS 7 and studies on its extracellular PHB degrading depolymerase enzyme. The bacterium isolated from soil samples of plastic contaminated sites of municipal area in Shahada, Maharashtra, Western India. It was identified as Stenotrophomonas sp. RZS 7 based on polyphasic approach. The bacterium grew well in minimal salt medium (MSM) and produced a zone (4.2 mm) of PHB hydrolysis on MSM containing PHB as the only source of nutrient. An optimum yield of enzyme was obtained on the fifth day of incubation at 37 °C and at pH 6.0. Further increase in enzyme production was recorded with Ca2+ ions, while other metal ions like Fe2+ (1 mM) and chemical viz. mercaptoethanol severally affected the production of enzyme.

Plant growth promotion and root colonization by EPS producing Enterobacter sp. RZS5 under heavy metal contaminated soil.

The heavy metal resistant bacterium isolated from field soil and identified as Enterobacter sp. RZS5 tolerates a high concentration (100-2000 µM) of various heavy metal ions such as Mn2+, Ni2+, Zn2+, Cu2+, CO2+ and Fe2+ when grown in such environment and produces exopolysaccharides (EPS). Here, we have demonstrated EPS production by Enterobacter sp. RZS5 during 60 h of growth in yeast extract mannitol broth (YEMB). The yield increased by two fold after the addition of 60 µM of Ca2+; 50 µM of Fe2+ and 60 µM of Mg2+ ions in YEMB, and the optimization of physico-chemical parameters. EPS was extracted with 30% (v/v) of isopropanol as against the commonly used 50% (v/v) isopropanol method. EPS-rich broth promoted seed germination, shoot height, root length, number of leaves and chlorophyll content of wheat (Triticum aestivum) seed and peanut (Arachis hypogaea) seed. The higher colony-forming unit of Enterobacter sp. in soil inoculated with EPS rich broth of Enterobacter sp. indicated the root colonizing potential and rhizosphere competence of the isolate. The FTIR spectra of the EPS extract confirmed the presence of the functional group characteristics of EPS known to exhibit a high binding affinity towards certain metal ions. This overall growth and vigour in plants along with the effective root colonization, reflected the potential of the isolate as an efficient bio-inoculant in bioremediation.

Production of biocontrol traits by banana field fluorescent Pseudomonads and comparison with chemical fungicide.

Pseudomonas aeruginosa isolated from banana field rhizosphere produced different antifungal metabolites like bactriocin, hydrogen cyanide and siderophore. Bacteriocinogenic, siderophoregenic, and HCN rich broth of isolate inhibited the growth of phytopathogen like Aspergilus niger, Aspergilus flavus, Fusarium oxysporum and Alternaria alternata. The isolate exhibited more antifungal activity and comparatively low MIC vis-a-vis commonly used copper based systemic chemical fungicide;bil cop.

Formulation and evaluation of s-(-)-amlodipine besylate and nebivolol hydrochloride tablets.

The objective of the present study was to develop a tablet formulation of S-(-)-amlodipine besylate chiral separation drug and nebivolol hydrochloride for better management of hypertension, while reducing or avoiding undesirable adverse effects, which are often associated with administration of a racemic mixture of amlodipine. The composition containing the optically pure S-(-)- isomer of amlodipine 2.5 mg has calcium channel blocking activity and, nebivolol hydrochloride 5 mg has beta-receptor blocking activity.The study was also carried out to design a suitable dissolution medium for S-(-) - amlodipine besylate and nebivolol hydrochloride. Amlodipine besylate and nebivolol hydrochloride had maximum solubility in pH 1.2 and thus pH 1.2 was selected as the most suitable media for S-(-) - amlodipine besylate and nebivolol hydrochloride dissolution studies. The RSD below 2% indicated insignificant batch-to-batch variation. The accelerated stability study of the optimized formulation was performed as the ICH guidelines. The results indicated no change in optical rotation of S-(-) - amlodipine besylate. Hence, combination of two drugs can be formulated into the tablet by wet granulation technique having satisfactory release profile.

Purification of alpha-glucosidae and invertase from bakers' yeast on modified polymeric supports.

In the present work Amberlite XAD-16 and Indion NPA-1, Polystyrene Divinylbenzene macroreticular spherical resins, have been evaluated quantitatively as supports for the adsorption and isolation of the yeast proteins and the enzymes, invertase and alpha-glucosidase. Modification of these supports has been carried out by surface grafting using acrylate polymers to reduce the hydrophobicity and nonspecific adsorption of proteins. Good grafting efficiency, in excess of 90%, has been obtained using ultrasonic irradiation for the surface activation of polystyrene resins. XAD-16 has higher adsorption capacities for the total yeast proteins as well as for both the enzymes, alpha-glucosidase and invertase, than NPA-1 in its respective native and grafted form. Adsorption capacities of XAD-16 and NPA-1 in their respective native and grafted forms for alpha-glucosidase are higher than the capacities for invertase. Nonspecific adsorption of total proteins has been reduced considerably after the grafting of acrylate polymers on hydrophobic supports. At the same time selectivity for the adsorption of both the enzymes has been enhanced on grafted supports. The overall solid-liquid adsorption mass transfer coefficient values (Kla) estimated for adsorption of invertase on XAD are lower than those for alpha-glucosidase. Native and grafted resins could be regenerated and reused for adsorption of alpha-glucosidase for two regeneration cycles studied. Storage stability of invertase and alpha-glucosidase is the same on native and grafted form of XAD-16 and is more than the enzymes in the free form.

Open lung biopsy for diffuse infiltrative lung disease.

The purpose of this study was to determine the most appropriate site of biopsy in patients with diffuse infiltrative lung disease (DILD). Twenty patients were evaluated. During open lung biopsy, a representative region (inflamed and least fibrotic) of the radiographically most involved lobe was identified and a biopsy done. A second biopsy specimen was obtained from an adjacent accessible lobe. The biopsy specimen from each lobe was processed separately, and a descriptive histologic report was generated for each of the two lobes. Tissue was cultured for bacteria, fungi, and mycobacteria. In 17 patients, the second biopsy site had fewer roentgenographic abnormalities than the radiographically most involved lobe. In 3 patients, the number of radiographic abnormalities was equal in all lobes. The same pathologic diagnosis was reached by histologic examination of the two biopsy specimens in 8 of 10 patients with acute DILD and in 10 of 10 patients with chronic DILD. In 2 patients, the biopsy specimen from the radiographically most involved lobe showed pathologic features not seen in the other specimen. Cultures from both biopsy specimens were grown separately in 6 patients. Fungi (n = 2) and bacteria (n = 1) were isolated from the radiographically most involved lobe (n = 2) or from the lobe of initial lung infiltration (n = 1) in 3 patients. When biopsy specimens are obtained from a representative region of the radiographically most involved lobe in patients with DILD, biopsy of other lobes is unnecessary.

Defective brain microtubule assembly in Alzheimer's disease.

Brains obtained within 2-4 hours post mortem and histopathologically confirmed for Alzheimer's disease and non-Alzheimer brains from age-matched controls were examined for in-vitro assembly of microtubules and neurofilaments. Microtubule assembly was observed only in control but not in Alzheimer brains, and neurofilaments were obtained from both types of brain. The microtubule-associated protein tau, which stimulates assembly of microtubules from tubulin, was abnormally phosphorylated in Alzheimer but not in control brain microtubule preparations. Alzheimer brains did not show the presence of any inhibitor of microtubule assembly or any abnormality of tubulin. DEAE-dextran, a polycation which mimics tau in stimulating microtubule assembly, induced the assembly of microtubules in Alzheimer brain. Tubulin from both normal and Alzheimer brains was labelled on western blots by a monoclonal antibody to the tyrosinylated carboxy-terminal epitope of alpha tubulin. These studies suggest that in Alzheimer's disease tubulin can be assembled into brain microtubules, but the process is defective, probably because of abnormal phosphorylation of tau. This post-translational alteration of tau might be the cause of the neurofibrillary abnormality in Alzheimer's disease.