Bio: P.S.R. Babu is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Penicillin amidase & Glutaraldehyde. The author has an hindex of 1, co-authored 1 publications receiving 24 citations.
TL;DR: The whole cell immobilization technique has been optimized for different process parameters and the granular catalyst has good mechanical strength, low protein leachability, and high retention of penicillin amidase activity.
Abstract: A method for catalyst development has been suggested for immobilizing whole E. coli cells containing penicillin amidase. Conventional methods have limitations, such as permeation of substrate and product through cellular membranes, leaching of protein and other cellular components into the reaction phase, lower specific activity compared to immobilized enzyme system, etc. The whole cell immobilization technique has been optimized for different process parameters. The most suitable conditions for this process were pH, 4.25; cell concentration, 3.75%; concentration of glutaraldehyde, 1.5%; level of bovine serum albumin as additional support, 2 mg ml −1 . The reaction was continued for 2 h. The granular catalyst has good mechanical strength, low protein leachability, and high retention of penicillin amidase activity .
TL;DR: It finally appeared that conductometric biosensors using algae seemed more sensitive than bioassays to detect low levels of cadmium ions (the detection limit for the first experiments was 1 ppb of Cd2+).
Abstract: A novel biosensor based on immobilised whole cell Chlorella vulgaris microalgae as a bioreceptor and interdigitated conductometric electrodes as a transducer has been developed and tested for alkaline phosphatase activity (APA) analysis. These sensors were also used for the detection of toxic compounds, namely cadmium ions, in aquatic habitats. Algae were immobilised inside bovine serum albumin (BSA) membranes cross-linked with glutaraldehyde vapours. The detection of the local conductivity variations caused by algae enzymatic reactions could be achieved. The inhibition of C. vulgaris microalgae Alkaline phosphatase activities in presence of cadmium ions was measured. These results were compared with measurements in bioassays. It finally appeared that conductometric biosensors using algae seemed more sensitive than bioassays to detect low levels of cadmium ions (the detection limit for the first experiments was 1 ppb of Cd2+). The main advantages of these alkaline phosphatase biosensors consist of their high specificity in regard to the toxic compounds they enable to detect, but also on their high stability since contrary to enzymatic biosensors, they use whole algae cells with APs on their walls.
TL;DR: The current clinical status of probiotics is summarized, the promises and challenges of current immobilization technologies are examined, the concept of artificial cells for effective delivery of therapeutic bacterial cells are presented, and microencapsulation in “artificial cells” is presented.
Abstract: Scientific evidence in the prevention and treatment of various disorders is accumulating regarding probiotics. The health benefits supported by adequate clinical data include increased resistance to infectious disease, decreased duration of diarrhea, management of inflammatory bowel disease, reduction of serum cholesterol, prevention of allergy, modulation of cytokine gene expression, and suppression of carcinogen production. Recent ventures in metabolic engineering and heterologous protein expression have enhanced the enzymatic and immunomodulatory effects of probiotics and, with time, may allow more active intervention among critical care patients. In addition, a number of approaches are currently being explored, including the physical and chemical protection of cells, to increase probiotic viability and its health benefits. Traditional immobilization of probiotics in gel matrices, most notably calcium alginate and κ-carrageenan, has frequently been employed, with noted improvements in viability during freezing and storage. Conflicting reports exist, however, on the protection offered by immobilization from harsh physiologic environments. An alternative approach, microencapsulation in “artificial cells,” builds on immobilization technologies by combining enhanced mechanical stability of the capsule membrane with improved mass transport, increased cell loading, and greater control of parameters. This review summarizes the current clinical status of probiotics, examines the promises and challenges of current immobilization technologies, and presents the concept of artificial cells for effective delivery of therapeutic bacterial cells.
TL;DR: Results show that ferulic acid can be produced using microencapsulated Lactobacillus fermentum with significant levels of biological feruloyl esterase activity.
Abstract: Biotechnological production of ferulic acid, a precursor of vanillin, is an attractive alternative for various industries due to the high price and demand for natural ferulic acid. Feruloyl esterase has been identified as a key enzyme involved in microbial transformations of ferulic acid to vanillin. Several fungal feruloyl esterases have been purified and characterized for their use in the production of ferulic acid. This paper, for the first time, discusses the use of lactic acid bacteria for the production of ferulic acid. Specifically, we have used Lactobacillus cells and microencapsulation so that ferulic acid can be produced continuously using various types of fermentation systems. Bacteria were encapsulated in alginate-poly-L-lysine-alginate (APA) microcapsules, and the production of ferulic acid by lactobacilli was detected using a real-time high-performance liquid chromatography (HPLC)-based assay. Results show that ferulic acid can be produced using microencapsulated Lactobacillus fermentum (ATCC 11976) with significant levels of biological feruloyl esterase activity.
TL;DR: In this article, a whole cell based biosensor is prepared by immobilizing Chlorella sp. microbes over glassy carbon electrode, which is optimized for characteristics like substrate concentration, pH, response time, and durability.
Abstract: Whole cell based biosensor is prepared by immobilizing Chlorella sp. microbes over glassy carbon electrode. The proposed biosensor is optimized for characteristics like substrate concentration, pH, response time, and durability. The electrode responds linearly in concentration range of 10 −14 M to 10 −6 M for mercury and showed its rare selectivity over silver, alkali metals, alkaline earth metals and transition metals with an expected life of 14 days.
TL;DR: It is found that the unique surface properties of diamond reduce the electrode fouling problem commonly encountered with metal electrodes.
Abstract: A whole-cell environmental biosensor was fabricated on a diamond electrode. Unicellular microalgae Chlorella vulgaris was entrapped in the bovine serum albumin (BSA) membrane and immobilized directly onto the surface of a diamond electrode for heavy metal detection. We found that the unique surface properties of diamond reduce the electrode fouling problem commonly encountered with metal electrodes. The cell-based diamond biosensor can attain a detection limit of 0.1 ppb for Zn2+ and Cd2+, and exhibits higher detection sensitivity and stability compared to platinum electrodes.