Impact of process parameters on chitinase production by an alkalophilic marine Beau6eria bassiana in solid state fermentation

A chitinolytic fungus, Beau6eria bassiana was isolated from marine sediment and significant process parameters influencing chitinase production in solid state fermentation using wheat bran were optimised. The organism was strongly alkalophilic and produced maximum chitinase at pH 9·20. The NaCl and colloidal chitin requirements varied with the type of moistening medium used. Vegetative (mycelial) inoculum was more suitable than conidial inoculum for obtaining maximal enzyme yield. The addition of phosphate and yeast extract resulted in enhancement of chitinase yield. After optimisation, the maximum enzyme yield was 246·6 units g 1 initial dry substrate (U gIDS 1). This is the first report of the production of chitinase from a marine fungus.

Utilization of prawn waste for chitinase production by the marine fungus Beauveria bassiana by solid state fermentation

Prawn waste, a chitinous solid waste of the shell®sh processing industry, was used as a substrate for chitinase production by the marine fungus Beauveria bassiana BTMF S10, in a solid state fermentation (SSF) culture. The process parameters in¯uencing SSF were optimized. A maximum chitinase yield of 248.0 units/g initial dry substrate (U/gIDS) was obtained in a medium containing a 5:1 ratio (w/v) of prawn waste/sea water, 1% (w/w) NaCl, 2.5% (w/w) KH2PO4, 425±600 lm substrate particle size at 27 °C, initial pH 9.5, and after 5 days of incubation. The presence of yeast extract reduced chitinase yield. The results indicate scope for the utilization of shell®sh processing (prawn) waste for the industrial production of chitinase by using solid state fermentation.

L-Glutaminase production by marine Beau6eria sp. under solid state fermentation

Extracellular L-glutaminase production by Beau6eria sp., isolated from marine sediment, was observed during solid state fermentation using polystyrene as an inert support. Maximal enzyme production (49.89 U:ml) occurred at pH 9.0, 27°C, in a seawater based medium supplemented with L-glutamine (0.25% w:v) as substrate and D-glucose (0.5% w:v) as additional carbon source, after 96 h of incubation. Enzyme production was growth associated. Results indicate scope for production of salt tolerant L-glutaminase using this marine fungus

Production, purification and partial characterization of a novel protease from marine Engyodontium album BTMFS10 under solid state fermentation

Engyodontium album isolated from marine sediment produced protease, which was active at pH 11. Process parameters influencing the production of alkaline protease by marine E. album was optimized. Particle size of <425 mm, 60% initial moisture content and incubation at 25 8C for 120 h were optimal for protease production under solid state fermentation (SSF) using wheat bran. The organism has two optimal pH (5 and 10) for maximal enzyme production. Sucrose as carbon source, ammonium hydrogen carbonate as additional inorganic nitrogen source and amino acid leucine enhanced enzyme production during SSF. The protease was purified and partially characterized. A 16-fold purified enzyme was obtained after ammonium sulphate precipitation and ion-exchange chromatography. Molecular weight of the purified enzyme protein was recorded approximately 38 kDa by SDS-PAGE. The enzyme showed maximum activity at pH 11 and 60 8C. Activity at high temperature and high alkaline pH suggests suitability of the enzyme for its application in detergent industry

Impact of process parameters on L-glutaminase production by marine Vibrio costicola in solid state fermentation using polystyrene as an inert support

Process parameters influencing e-glutaminase production by marine Vibrio costicola in solid state fermentation (SSF) using polystyrene as an inert support were optimised. Maximal enzyme yield (157 U/g dry substrate) was obtained at 2% (w/w) t:glutamine, 35°C and pH 7.0 after 24 h. Maltose and potassium dihydrogen phosphate at 1% (w/w) concentration enhanced enzyme yield by 23 and 18%, respectively, while nitrogen sources had an inhibitory effect. Leachate with high specific activity for glutaminase (4.2 U/mg protein) and low viscosity (0-966 Ns/m 2) was recovered from the polystyrene SSF system

Extracellular β-glucosidase Production by a Marine Aspergillus sydowii BTMFS 55 under Solid State Fermentation Using Statistical Experimental Design

A potential fungal strain producing extracellular β-glucosidase enzyme was isolated from sea water and identified as ^ëéÉêJ Öáääìë=ëóÇçïáá BTMFS 55 by a molecular approach based on 28S rDNA sequence homology which showed 93% identity with already reported sequences of ^ëéÉêÖáääìë=ëóÇçïáá in the GenBank. A sequential optimization strategy was used to enhance the production of β-glucosidase under solid state fermentation (SSF) with wheat bran (WB) as the growth medium. The two-level Plackett-Burman (PB) design was implemented to screen medium components that influence β-glucosidase production and among the 11 variables, moisture content, inoculums, and peptone were identified as the most significant factors for β-glucosidase production. The enzyme was purified by (NH4)2SO4 precipitation followed by ion exchange chromatography on DEAE sepharose. The enzyme was a monomeric protein with a molecular weight of ~95 kDa as determined by SDS-PAGE. It was optimally active at pH 5.0 and 50°C. It showed high affinity towards éNPG and enzyme has a hã and sã~ñ of 0.67 mM and 83.3 U/mL, respectively. The enzyme was tolerant to glucose inhibition with a há of 17 mM. Low concentration of alcohols (10%), especially ethanol, could activate the enzyme. A considerable level of ethanol could produce from wheat bran and rice straw after 48 and 24 h, respectively, with the help of p~ÅÅÜ~êçãóÅÉë=ÅÉêÉîáëá~É in presence of cellulase and the purified β-glucosidase of ^ëéÉêÖáääìë=ëóÇçïáá BTMFS 55.

Purification and Characterization of an Anti-cancer Enzyme Produced by Marine Vibrio Costicola Under A Novel Solid State Fermentation Process

L - Glutaminase, a therapeutically and industrially important enzyme, was produced from marine Vibrio costicola by a novel solid state fermentation process using polystyrene beads as inert support. The new fermentation system offered several advantages over the conventional systems, such as the yield of leachate with minimum viscosity and high specific activity for the target product besides facilitating the easy estimation of biomass. The enzyme thus produced was purified and characterised. It was active at physiological pH, showed high substrate specificity towards L - glutamine and had a Km value of 7.4 x 10-2 M. It also exhibited high salt and temperature tolerance indicating good scope for its industrial and therapeutic applications

Optimization of Lignin Peroxidase, Manganese Peroxidase, and Lac Production from Ganoderma lucidum Under Solid State Fermentation of Pineapple Leaf

This study was undertaken to isolate ligninase-producing white-rot fungi for use in the extraction of fibre from pineapple leaf agriwaste. Fifteen fungal strains were isolated from dead tree trunks and leaf litter. Ligninolytic enzymes (lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac)), were produced by solid-state fermentation (SSF) using pineapple leaves as the substrate. Of the isolated strains, the one showing maximum production of ligninolytic enzymes was identified to be Ganoderma lucidum by 18S ribotyping. Single parameter optimization and response surface methodology of different process variables were carried out for enzyme production. Incubation period, agitation, and Tween-80 were identified to be the most significant variables through Plackett-Burman design. These variables were further optimized by Box-Behnken design. The overall maximum yield of ligninolytic enzymes was achieved by experimental analysis under these optimal conditions. Quantitative lignin analysis of pineapple leaves by Klason lignin method showed significant degradation of lignin by Ganoderma lucidum under SSF

Simulation and Design of a high speed Solid State Switch for Excimer Laser

Excimerlaser sind gepulste Gaslaser, die Laseremission in Form von Linienstrahlung – abhängig von der Gasmischung – im UV erzeugen. Der erste entladungsgepumpte Excimerlaser wurde 1977 von Ischenko demonstriert. Alle kommerziell verfügbaren Excimerlaser sind entladungsgepumpte Systeme. Um eine Inversion der Besetzungsdichte zu erhalten, die notwendig ist, um den Laser zum Anschwingen zu bekommen, muss aufgrund der kurzen Wellenlänge sehr stark gepumpt werden. Diese Pumpleistung muss von einem Impulsleistungsmodul erzeugt werden. Als Schaltelement gebräuchlich sind Thyratrons, Niederdruckschaltröhren, deren Lebensdauer jedoch sehr limitiert ist. Deshalb haben sich seit Mitte der 1990iger Jahre Halbleiterschalter mit Pulskompressionsstufen auch in dieser Anwendung mehr und mehr durchgesetzt. In dieser Arbeit wird versucht, die Pulskompression durch einen direkt schaltenden Halbleiterstapel zu ersetzen und dadurch die Verluste zu reduzieren sowie den Aufwand für diese Pulskompression einzusparen. Zudem kann auch die maximal mögliche Repetitionsrate erhöht werden. Um die Belastung der Bauelemente zu berechnen, wurden für alle Komponenten möglichst einfache, aber leistungsfähige Modelle entwickelt. Da die normalerweise verfügbaren Daten der Bauelemente sich aber auf andere Applikationen beziehen, mussten für alle Bauteile grundlegende Messungen im Zeitbereich der späteren Applikation gemacht werden. Für die nichtlinearen Induktivitäten wurde ein einfaches Testverfahren entwickelt um die Verluste bei sehr hohen Magnetisierungsgeschwindigkeiten zu bestimmen. Diese Messungen sind die Grundlagen für das Modell, das im Wesentlichen eine stromabhängige Induktivität beschreibt. Dieses Modell wurde für den „magnetic assist“ benützt, der die Einschaltverluste in den Halbleitern reduziert. Die Impulskondensatoren wurden ebenfalls mit einem in der Arbeit entwickelten Verfahren nahe den späteren Einsatzparametern vermessen. Dabei zeigte sich, dass die sehr gebräuchlichen Class II Keramikkondensatoren für diese Anwendung nicht geeignet sind. In der Arbeit wurden deshalb Class I Hochspannungs- Vielschicht- Kondensatoren als Speicherbank verwendet, die ein deutlich besseres Verhalten zeigen. Die eingesetzten Halbleiterelemente wurden ebenfalls in einem Testverfahren nahe den späteren Einsatzparametern vermessen. Dabei zeigte sich, dass nur moderne Leistungs-MOSFET´s für diesen Einsatz geeignet sind. Bei den Dioden ergab sich, dass nur Siliziumkarbid (SiC) Schottky Dioden für die Applikation einsetzbar sind. Für die Anwendung sind prinzipiell verschiedene Topologien möglich. Bei näherer Betrachtung zeigt sich jedoch, dass nur die C-C Transfer Anordnung die gewünschten Ergebnisse liefern kann. Diese Topologie wurde realisiert. Sie besteht im Wesentlichen aus einer Speicherbank, die vom Netzteil aufgeladen wird. Aus dieser wird dann die Energie in den Laserkopf über den Schalter transferiert. Aufgrund der hohen Spannungen und Ströme müssen 24 Schaltelemente in Serie und je 4 parallel geschaltet werden. Die Ansteuerung der Schalter wird über hochisolierende „Gate“-Transformatoren erreicht. Es zeigte sich, dass eine sorgfältig ausgelegte dynamische und statische Spannungsteilung für einen sicheren Betrieb notwendig ist. In der Arbeit konnte ein Betrieb mit realer Laserkammer als Last bis 6 kHz realisiert werden, der nur durch die maximal mögliche Repetitionsrate der Laserkammer begrenzt war.

Solid-state interconversions of coordination networks and hydrogen-bonded salts

Thermal or chemical treatment of crystalline 4,4-bipyridinium salts of [MCl4]2- (M=Co, Zn, Fe, or Pt) leads to HCl loss and formation of coordination network solids [{MCl2(4,4-bipy)}n]. For M=Co, Zn, and Fe, these solids can also be prepared by mechanochemical means. Their exposure to HCl vapor or the mechanochemical reaction of metal dichlorides with [4,4-H2bipy]Cl2 gives [4,4-H2bipy]2+ salts of [CoCl4]2-, [ZnCl4]2-, and, for the first time, [FeCl4]2-.

A novel copper(I) complex that is a monomeric single helix in solid state but a dimeric double helix in solution

Single helical [(CuL)-L-I]ClO4.12CH(2)Cl(2) (L=1:2 condensate of benzil dihydrazone and 2-acetylpyridine) unfolds and coils up in CH2Cl2 solution to generate double helical [(Cu2L2)-L-I](2+).

Stepwise self-assembly of a tripeptide from molecular dimers to supramolecular beta-sheets in crystals and amyloid-like fibrils in the solid state

The terminally protected tripeptide Boc-Ala(1)-Leu(2)-Ala(3)-OMe 1 forms antiparallel hydrogen-bonded dimers of two different conformers in the asymmetric unit and the individual dimers then self-associate to form supramolecular beta-sheet structures in crystals and amyloid-like fibrils in the solid state.

Can a consecutive double turn conformation be considered as a peptide based molecular scaffold for supramolecular helix in the solid state?

Helices and sheets are ubiquitous in nature. However, there are also some examples of self-assembling molecules forming supramolecular helices and sheets in unnatural systems. Unlike supramolecular sheets there are a very few examples of peptide sub-units that can be used to construct supramolecular helical architectures using the backbone hydrogen bonding functionalities of peptides. In this report we describe the design and synthesis of two single turn/bend forming peptides (Boc-Phe-Aib-Ile-OMe 1 and Boc-Ala-Leu-Aib-OMe 2) (Aib: alpha-aminoisobutyric acid) and a series of double-turn forming peptides (Boc-Phe-Aib-IIe-Aib-OMe 3, Boc-Leu-Aib-Gly-Aib-OMe 4 and Boc-gamma-Abu-Aib-Leu-Aib-OMe 5) (gamma-Abu: gamma-aminobutyric acid). It has been found that, in crystals, on self-assembly, single turn/bend forming peptides form either a supramolecular sheet (peptide 1) or a supramolecular helix (peptide 2). unlike self-associating double turn forming peptides, which have only the option of forming supramolecular helical assemblages. (c) 2005 Elsevier Ltd. All rights reserved.