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Laccase- and Peroxidase-Free Tyrosinase Production by Isolated Microbial Strain
( Sambasiva Rao K. R. S. ),( N. K. Tripathy ),( Y. Mahalaxmi ),( R. S. Prakasham ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.2
Laccase- and peroxidase-free tyrosinase has commercial importance in the production of L-3, 4-dihydroxyphenylalanine (L-DOPA), which is mainly used in the treatment of Parkinson`s disease. In the present study, isolation of an actinomycetes microbial strain capable of producing only tyrosinase is reported. Among all soil isolates, three individual colonies revealed black color around the colony in the presence of tyrosine. Further screening for laccase and peroxidase activities using syringaldazine denoted that one of the isolates, designated as RSP-T1, is laccase and peroxidase negative and produces only tyrosinase. The microbe was authenticated as Streptomyces antibioticus based on 16S ribotyping. Effective growth of this isolate was noticed with the use of medium (pH 5.5) containing casein acid hydrolysate (10.0 g/l), K2HPO4 (5.0 g/l), MgSO4 (0.25 g/l), L-tyrosine (1.0 g/l), and agar (15 g/l). The scanning electron micrograph depicted that the microbe is highly branched and filamentous in nature. The enzyme production was positively regulated in the presence of copper sulfate. The impact of different fermentation parameters on tyrosinase production depicted that the maximized enzyme titer values were observed when this isolate was grown at 6.5 pH and at 30oC temperature under agitated conditions (220 rpm). Among all the studied physiological parameters, agitation played a significant role on tyrosinase production. Upon optimization of the parameters, the yield of tyrosinase was improved more than 100% compared with the initial yield.
K. Sambasiva Rao,T. V. Beatriceveena,C. S. Angani,Lucky Agarwal 한국자기학회 2020 Journal of Magnetics Vol.25 No.3
Pulsed eddy current (PEC) testing is an electromagnetic nondestructive evaluation (NDE) technique which is used for detection and classification of flaws. This paper presents an approach for the extraction of novel timedomain flaw parameters viz. amplitude ratio (V1/V0) and time constant (τ) for detection and classification of different flaws. Experiments are carried out on stainless steel (SS-316) plate with artificial EDM notches whose width (1.0 mm & 3.0 mm) and depth (1.0 mm to 6.0 mm) varied. The proposed approach can classify both surface and sub-surface flaws in an 8.0 mm thick SS plate. The advantage of the proposed approach is that it doesn’t require a reference signal subtraction or signal processing methodologies for the detection and classification of flaws.
Yesudasu Bammidi,Chandra S Angani,K Sambasiva Rao,M. B. Kishore,G. Krishna Podagatlapalli,S. Sreedhar 한국자기학회 2022 Journal of Magnetics Vol.27 No.2
Failures in the industrial components are unavoidable due to material degradation from various sources, thus continuous monitoring and timely inspection is mandatory for structural safety. In the present study, the recently developed Transient Eddy Current Oscillations (TECO) method is used to detect wall-thinning in a stainless-steel plate. Unlike the conventional Eddy Current Testing impedance plane data a new interpretation method has been implemented to identify a thickness variation using the S-domain parameters. Furthermore, time and frequency spectral features are analysed to get more insight into the results. The decay time and the resonant frequency are the basis for the discussion to assess the wall thickness.
Rekha, V. P. B.,Ghosh, Mrinmoy,Adapa, Vijayanand,Oh, Sung-Jong,Pulicherla, K. K.,Sambasiva Rao, K. R. S. Hindawi Publishing Corporation 2013 BioMed research international Vol.2013 No.-
<P>The present study deals with the production of cold active polygalacturonase (PGase) by submerged fermentation using <I>Thalassospira frigidphilosprofundus</I>, a novel species isolated from deep waters of Bay of Bengal. Nonlinear models were applied to optimize the medium components for enhanced production of PGase. Taguchi orthogonal array design was adopted to evaluate the factors influencing the yield of PGase, followed by the central composite design (CCD) of response surface methodology (RSM) to identify the optimum concentrations of the key factors responsible for PGase production. Data obtained from the above mentioned statistical experimental design was used for final optimization study by linking the artificial neural network and genetic algorithm (ANN-GA). Using ANN-GA hybrid model, the maximum PGase activity (32.54 U/mL) was achieved at the optimized concentrations of medium components. In a comparison between the optimal output of RSM and ANN-GA hybrid, the latter favored the production of PGase. In addition, the study also focused on the determination of factors responsible for pectin hydrolysis by crude pectinase extracted from <I>T. frigidphilosprofundus</I> through the central composite design. Results indicated 80% degradation of pectin in banana fiber at 20°C in 120 min, suggesting the scope of cold active PGase usage in the treatment of raw banana fibers.</P>