Marichetti Kuppuswami Gowthaman

Potentiometric biosensor for determination of urea in milk using immobilized Arthrobacter creatinolyticus urease.

The extracellular urease from Arthrobacter creatinolyticus was partially purified by ammonium sulfate precipitation and immobilized on PAN [poly(acrylonitrile-methylmethacrylate-sodium vinylsulfonate)] membrane. The urease immobilized PAN membrane exhibited an activity of 97.92U/cm(2) under the optimum conditions of 1.0% enzyme concentration, 15% glutaraldehyde, 24h immobilization time and temperature of 4°C. The changes in surface morphology of the membrane after immobilization were studied by SEM and ATR-FTIR analysis. Immobilized membrane was associated with potentiometric electrode for calibration of biosensor and the results showed a linear response for wide range of urea concentration from 1 to 100mM. The immobilized urease had good storage stability for a period of 70days at 4°C and could be effectively reused for 13cycles. Urease immobilized membrane was also employed in analysis of urea spiked milk samples.

Utilization of fish meal and fish oil for production of Cryptococcus sp. MTCC 5455 lipase and hydrolysis of polyurethane thereof

Fish meal has been used as an additional nitrogen source and fish oil as inducer for the growth and production of lipase from Cryptococcus sp. MTCC 5455. A response surface design illustrated that the optimum factors influencing lipase production were fish meal, 1.5xa0%, w/v, Na2HPO4, 0.2xa0%, w/v, yeast extract, 0.25xa0%, w/v and sardine oil, 2.0xa0%, w/v with an activity of 71.23xa0U/mL at 96xa0h and 25xa0°C, which was 48.39xa0% higher than the conventional one-factor-at-a-time method. The crude concentrated enzyme hydrolyzed polyurethane (PUR) efficiently and hydrolysis was 94xa0% at 30xa0°C and 96xa0h. The products, diethylene glycol and adipic acid were quantified by HPLC and scanning electron microscopic studies of the degraded polymer showed significant increase in size of the holes from 24 to 72xa0h of incubation. Hydrolysis of PUR within 96xa0h makes the lipase novel for disposal of PUR and provides an innovative solution to the problems created by plastic wastes.

Wealth from waste – beef extract for microbiological media from tannery solid waste

Lime fleshing waste is one of the major hazardous solid wastes from leather industry. Utilization of the waste is one of the appropriate strategies to address the environmental issues and to realize economical returns. A process of preparation of beef extract from limed fleshing waste has been developed. The beef extract prepared is intended for microbial application. According to the process developed, the alkalis present in the fleshing waste were neutralized and removed by washing. Then the fleshing waste was hydrolyzed thermally and the hydrolysate obtained was lyophilized. The prepared product was characterized. The characteristics of the prepared product were compared with those of a widely accepted market product (Hi-Media). The beef extract prepared was found to be in compliance with all the requirements of the relevant standard. The product was also found to perform similarly to Hi-Media beef extract. The chemistry of the product was studied using tools such as FT-IR, HPLC, Maldi-TOF, 13C NMR and 1H NMR. The product chemistry was found to be akin to that of the beef extract of Hi-Media.

Screening and production of a potent extracellular Arthrobacter creatinolyticus urease for determination of heavy metal ions

This paper describes the isolation of a potent extracellular urease producing microorganism, identified by 16S rRNA as Arthrobacter creatinolyticus MTCC 5604 and its medium optimization by classical one‐factor‐at‐a‐time method and central composite rotatable design (CCRD), a tool of response surface methodology (RSM). An optimal activity of 9.0u2009Uu2009ml−1 was obtained by classical method and statistical optimization of the medium resulted in an activity of 17.35u2009Uu2009ml−1 at 48u2009h and 30u2009°C. This activity was 4.91 times greater than the initial activity (3.53u2009Uu2009ml−1) from the basal medium and the enzyme showed maximum activity at pH 8.0 and 60u2009°C and was stable at pH 7.0–9.0 and temperatures up to 50u2009°C. Furthermore, the enzyme was assessed for its activity reduction by determining the inhibitory concentration (IC50) of heavy metal ions and the inhibition of urease was in the order of Cu(II)u2009>u2009Cd(II)u2009>u2009Zn(II)u2009>u2009Ni(II). Urease was highly sensitive to Cu(II) and its inhibition was 94% and 100% in model solutions containing a mixture of Cu(II) with heavy metal ions Cd(II) and Zn(II), respectively. The results of these studies suggested that the enzyme could be utilized as sensors to determine the levels of Cu(II) ions in industrial effluents, contaminated soil and ground water.

Inexpensive α-amylase production and application for fiber splitting in leather processing

Recently, the production of superior quality enzymes using waste sources has promoted greater research interest due to their enhanced enzyme activity, selectivity and stability. In this work, the production of enzyme α-amylase from wheat bran using a solid-state fermentation technique is presented. Further, reasonably high production of liquid α-amylase was achieved with enhanced activity and stability. In order to check the benefits of α-amylase, a fiber opening process using an in-house α-amylase has been developed for goatskins, in an attempt to reduce pollution from beam house processes, while doing a cost and environment benefit analysis. In addition, the effect of fiber opening by the developed enzyme was compared with a couple of commercial enzyme products and chemical processes (lime and sodium sulphide). After the fiber splitting process, the pelt was made into crust leather and the effect of fiber splitting on the strength properties related morphological changes of the crust leather samples were thoroughly investigated. The findings revealed that the inexpensive enzyme produced in this study displayed lower pollution load (COD, TS), with significant release of inter-fibrillary materials. Another significant observation was that the enzyme concentrate from the SSF process showed equivalent fiber splitting with lower cost than chemical-based processes and the commercially used powder enzyme products. Finally the developed inexpensive enzyme will act as a better replacement for chemical processes with lower cost.

PROCESS STRATEGIES FOR ALKALINE LIPASE PRODUCTION USING Aspergillus Niger MTCC 2594

We report scale-up production of alkaline lipases from Aspergillus niger MTCC 2594 using submerged stir tank fermenter (SSTF). The batch culture experiments and biomass studies suggest that olive oil used in the process reduced enzyme yield. We found that the addition of olive oil intermittently might be a potential fed-batch strategy to improve lipase production using Aspergillus niger MTCC 2594.

Fabrication and characterization of dual acting oleyl chitosan functionalised iron oxide/gold hybrid nanoparticles for MRI and CT imaging

Bionanocomposites fabricated using metal nanoparticles serve a wide range of biomedical applications viz., site targeted drug delivery, imaging etc. Theranostics emerge as an important field of science, which focuses on the use of single entity for both disease diagnosis and treatment. The present work aimed at designing a multifunctional nanocomposite comprising of iron/gold hybrid nanoparticles, coated with oleyl chitosan and conjugated with methotrexate. The HR-TEM images revealed the spherical nature of the composite, while its nontoxic and biocompatible property was proved by the MTT assay in NIH 3T3 cells and hemolysis assay. Though the VSM results exhibited the magnetic property, the MRI phantom images and X-ray contrast images demonstrated the potential of the composite to be used as contrast agent. Thus the prepared nanocomposite possess good cytocompatibility, magnetic property and also high X-ray attenuation, wherein it could serve as a novel platform for both MRI and CT diagnosis, as well as drug conjugation could aid in targeted drug delivery.