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).

• MeSH
• Bacteria metabolismus   MeSH
• biodegradace MeSH
• biotechnologie metody   MeSH
• celulosa chemie   metabolismus   MeSH
• houby metabolismus   MeSH
• plastické hmoty chemická syntéza   metabolismus   MeSH
• polyestery metabolismus   MeSH
• polymery MeSH
• rostliny metabolismus   MeSH
• škrob chemie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• celulosa MeSH
• plastické hmoty MeSH
• polyestery MeSH
• polymery MeSH
• škrob MeSH

Among 30 species of filamentous fungi isolated from Brazilian soil, Aspergillus caespitosus produced and secreted the highest levels of alkaline phosphatase in culture medium supplemented with xylan. The extracellular alkaline phosphatase was purified by DEAE-cellulose and concanavalin A-sepharose chromatography. The enzyme was a glycoprotein containing up to 56% sugar with molar mass of 134.8 kDa, according to gel filtration in Sepharose CL-6B, and 57 kDa according to SDS-PAGE. Nondenaturing electrophoresis (6% PAGE) of the purified enzyme produced a single band, suggesting that the native enzyme was a homodimer. Optima of temperature and pH were 75 degrees C and 8.5, respectively. The enzyme was stable at 50 degrees C and its activity was enhanced by 95% in the presence of Mg2+ (1 mmol/L). 4-Nitrophenyl phosphate was the preferentially hydrolyzed substrate with K(m) and upsilon lim values of 74 mumol/L and 285 mumol/s, in the absence, and 90 mumol/L and 418 mumol/s, in the presence of Mg2+, respectively. The enzyme also hydrolyzed other phosphorylated amino acids (O-phosphothreonine, O-phosphotyrosine, O-phosphoserine).

• MeSH
• alkalická fosfatasa chemie   izolace a purifikace   metabolismus   MeSH
• Aspergillus enzymologie   MeSH
• glykoproteiny chemie   izolace a purifikace   metabolismus   MeSH
• inhibitory enzymů farmakologie   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• molekulová hmotnost MeSH
• sacharidy MeSH
• substrátová specifita MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alkalická fosfatasa MeSH
• glykoproteiny MeSH
• inhibitory enzymů MeSH
• sacharidy MeSH