L-lactic acid fermentation method by using polyvinyl alcohol to solidify rhizopus oryzae

Abstract

The invention discloses an L-lactic acid fermentation method by using polyvinyl alcohol to solidify rhizopus oryzae. The method comprises the following steps: heating polyvinyl alcohol and sodium alginate in a boiling water bath to be jointly dissolved; mixing with a rhizopus oryzae spore suspension; using an injector to drip the mixed solution to a saturated boric acid solution containing calcium chloride while using a magnetic stirrer to continuously stir so that particles are spherical and good immobilized particles can be hardened at a low temperature; and then, treating by a monobasic sodium phosphate solution and washing with distilled water after solidified cells are propagated and grow so as to be used for the batch fermentation and the repetitive batch fermentation of the L-lactic acid. The improved L-lactic acid fermentation method by using the polyvinyl alcohol to solidify the rhizopus oryzae overcomes the defects of spherical carriers and poor permeability of the prior polyvinyl alcohol and has the advantages of great mechanism strength, large acid production amount, high acid production speed and good repetitive use effect.

Description

technical field

[0001] The invention relates to an improved method for fermenting L-lactic acid by polyvinyl alcohol-immobilized rhizopus oryzae. Background technique

[0002] Lactic acid, also known as 2-hydroxypropionic acid, molecular formula CH 3 CH(OH)COOH, one of the important organic acids, widely exists in the human body, animals, plants and microorganisms. It is a commonly used sour agent and preservative in the food industry, and is also an important raw materials. As the raw material of poly-L-lactic acid (PLA), an environmentally friendly biodegradable material, L-lactic acid has an increasing demand for lactic acid at home and abroad, and its development prospects are very broad. The source of lactic acid is mainly chemical synthesis and microbial fermentation production. Due to the production by fermentation method, the carbon source utilization rate is very high, even up to 100%, and renewable resources such as crop straw and forestry waste can be converted...