β-amylase production by a novel strain Paenibacillus chitinolyticus CKS1 using commercial and waste substrates

Abstract

Amylases are industrially important enzymes which could convert starch to glucose, maltose and oligosaccharides. A bacterial strain designated as Paenibacillus chitinolyticus CKS1which was isolated from the soil of the coniferous forest, produced β-amylases using different commercial and waste substrates. Maximum β-amylases activity of 0.820 U/mL was obtained using a sugar alcohol-isomaltidex (0.5% w/v), as a substrate for microorganism growth and enzyme production. After 48 h of fermentation in a medium that contained starch (0.5%, w/v) and 0.05% v/v of ethanol, CKS1 produced β-amylase with the activity of 0.518 U/mL. The latest trends in enzyme production include utilisation of various waste products, mainly of agroindustrial origin, as a substrate for microorganisms growth. The strain CKS1 was also able to grow and produce β-amylases by using plant waste material. The plant waste substrate (PWS) contained plant biomass that is left after the ethanol extraction of various medicinal herbs (marigold and chamomile flowers, artichoke leaf, lemon balm leaf, nettle leaf, thyme leaf, yarrow shoot, yellow gentian shoot, primrose shoot, valerian shoot and chestnut and hawthorn seeds).This mixture of dried plant biomass is dissposed as such as a waste. In a medium with 0.1% (w/v) of PWS, CKS1 produced β-amylases with a maximum activity of 0.569 U/mL. The results show the potential of utilising waste plant biomass, left after ethanol extraction of medicinal herbs, in production of amylases. The application of microorganisms in β-amylase production using waste substrate is economically and environmentally accepted.

Keywords

• paenibacillus chitinolyticus cks1
• fermentation
• β-amylase production
• sugar alcohol
• plant waste substrate (pws)