High-Molecular-Weight Amylase Activities from Bacteria Degrading Starch-Plastic Films

Frist observation and effect of fishery of seabed litter on sea bed by trawl survey Korea waters

Fisheries activities for supplying marine productions were excessively overwhelming. Furthermore in the competitive industrialization, the impact on marine ecosystems and fisheries resources are severe due to the increase of various seabed litter such as plastic materials, styrofoam and plastic bottles and the deterioration of the marine environment. Despite these seriously situation, very few studies of some sea of Korea have been carried out on sedimentary waste fishing. Also some fisheries and there are few reports on plastics present on the seabed of around Korea. This study investigated the distribution of seabed litter collected from the seabed and characteristics of each area by using the trawl gear of the survey vessel from February to November 2018. The weight of all seabed litter collected during the investigation was 62,541.5 kg km^-2, with a range of 0.2-15,019.7 kg km^-2. The most amount of seabed litter was collected from sea block 106 in the South Sea, followed by sea blocks 76 and 82 in the East Sea. Through this study, which was conducted for the first time in all sea in around Korea, it can be used as basic data to understand the current status of seabed litter in the seabed and to establish effective policies at the led by the government.

Novel Thermotolerant Amylase from Bacillus licheniformis Strain LB04: Purification, Characterization and Agar-Agarose

This study analyzed the thermostability and effect of calcium ions on the enzymatic activity of α-amylase produced by Bacillus licheniformis strain LB04 isolated from Espinazo Hot springs in Nuevo Leon, Mexico. The enzyme was immobilized by entrapment on agar-agarose beads, with an entrapment yield of 19.9%. The identification of the bacteria was carried out using 16s rDNA sequencing. The enzyme was purified through ion exchange chromatography (IEX) in a DEAE-Sephadex column, revealing a protein with a molecular weight of ≈130 kDa. The enzyme was stable at pH 3.0 and heat stable up to 80 °C. However, the optimum conditions were reached at 65 °C and pH 3.0, with a specific activity of 1851.7 U mg⁻¹ ± 1.3. The agar-agarose immobilized α-amylase had a hydrolytic activity nearly 25% higher when compared to the free enzyme. This study provides critical information for the understanding of the enzymatic profile of B. licheniformis strain LB04 and the potential application of the microorganisms at an industrial level, specifically in the food industry.

Biodegradable plastics from renewable sources

Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

Binding of Extracellular Carboxymethylcellulase Activity from the Marine Shipworm Bacterium to Insoluble Cellulosic Substrates

The binding of extracellular endoglucanase, a carboxymethylcellulase (CMCase), produced by the marine shipworm bacterium to insoluble cellulose substrates was investigated. Up to 70% of CMCase activity bound to cellulosic substrates, and less than 10% bound to noncellulosic substrates. CMCase binding to cellulose was enhanced in basal salt medium or sodium phosphate buffer containing 0.5 M NaCl. Increased cellulose particle size correlated with decreased CMCase binding. Also, cellulose treated with either 5 N NaOH or commercial cellulase reduced the CMCase binding to these surfaces. Pretreatment of CMCase preparations with 0.01% sodium dodecyl sulfate, 5% β-mercaptoethanol, and 5 mM EDTA or ethylene glycol-bis(β-aminoethyl ether)- N,N,N′,N′ -tetraacetic acid (EGTA) had little effect on binding to cellulose. While pretreatment of CMCase with trypsin, chymotrypsin, and pronase had little effect on CMCase enzymatic activity, the ability to bind to cellulose was greatly diminished by these treatments.