Optimization of cold-active chitinase production from the Antarctic bacterium, Sanguibacter antarcticus KOPRI 21702

Abstract

In the present study, cultivation conditions and medium components were optimized using statistical design and analysis to enhance the production of Chi21702, a cold-active extracellular chitinase from the Antarctic bacterium Sanguibacter antarcticus KOPRI 21702. Identification of significant carbon sources and other key elements was performed using a statistical design technique. Chitin and glycerol were selected as main carbon sources, and the ratio of complex nitrogen sources to carbon sources was determined to be 0.5. Among 15 mineral components included in basal medium, NaCl, Fe(C₆H₅O₇), and MgCl₂ were found to have the most influence on Chi21702 production. The optimal parameters of temperature, initial pH, and dissolved oxygen level were found to be 25°C, 6.5, and above 30% of air saturation, respectively. The maximum Chi21702 activity obtained under the optimized conditions was 90 U/L. Through statistical optimization methods, a 7.5-fold increase in Chi21702 production was achieved over unoptimized conditions. Chi21702 showed relatively high activity, even at low temperatures close to 0°C. The information obtained in the present study could be applied to the production of cold-active endochitinase on a large scale, suitable for a process at low temperature in industry.

A new strategy for improved glutathione production from Saccharomyces cerevisiae: use of cysteine‐ and glycine‐rich chicken feather protein hydrolysate as a new cheap substrate

“…The aim was to provide the protein hydrolysate with high levels of K and Mg, moderate levels of Ca and Na but a low level of Fe. This is because many investigators have suggested that culture media should contain K and Mg at high levels, Na and Ca at moderate levels but Fe at a low level …”

Soil Bacterial Community Shifts after Chitin Enrichment: An Integrative Metagenomic Approach

“…Apart from their fundamental role in ecosystems functioning, chitin degraders and their enzymes received a particular attention during the last decade for numerous applications. Chitin degraders are candidates for in situ application as biocontrol agents of soil born plant-pathogenic fungi [11] , while shellfish wastes can be treated in the frame of enzymatic industrial processes, involving new and efficient chitinases characterized from environmental microbial communities [16] , [17] .…”

Engineering actinomycetes for biosynthesis of macrolactone polyketides

“…Similarly, while replacing the DesVII/DesVIII by substrate-flexible glycosyltransferase TylMII coupled with partner protein TylMIII derived from S. fradiae , a mycaminosyl derivative of tylactone (5- O -mycaminosyl tylactone) was produced [61]. Similarly, expression of complete biosynthetic pathways for the biosynthesis of TDP-3-demethyl- d -chalcose or TDP l -rhamnose together with the glycosyltransferase-auxiliary protein pair DesVII/DesVIII along with subsequent feeding of 16-membered ring macrolactone tylactone was fed to this engineered host, which in turn successfully produced 3- O -demethyl- d -chalcosyl, l -rhamnosyl, and d -quinovosyl derivatives [62]. Similarly, using S. venezuelae YJ003 and expression of complete biosynthetic pathways for the biosynthesis of TDP-3-dimethyl- d -chalcose or TDP- l -rhamnose together with DesVII/DesVIII, novel narbomycin derivative decorated with l -rhamnose or 3- O -demethyl- d -chalcose were generated.…”

“…Similarly, using S. venezuelae YJ003 and expression of complete biosynthetic pathways for the biosynthesis of TDP-3-dimethyl- d -chalcose or TDP- l -rhamnose together with DesVII/DesVIII, novel narbomycin derivative decorated with l -rhamnose or 3- O -demethyl- d -chalcose were generated. These novel analogs exhibited greater antibacterial activity than narbomycin and the clinically relevant erythromycin [62]. In another instance, for another aglycone YC-17, the native d -desosamine was replaced by d -quinovose, l -olivose, l -rhamnose, and d -boivinose to generate YC-17 glycoside analogs as d -quinovosyl-10-deoxymethynolide, l -olivosyl-10-deoxymethynolide, l -rhamnosyl-10-deoxymethynolide, and d -boivinosyl-10-deoxymethynolide respectively by expression of gene cassette responsible for biosynthesis of respective deoxysugars (Fig.…”