4 results about "Microbial transformation" patented technology

This invention provides an oleic acid hydratase OhyA1 mutant, its preparation method, and its applications, belonging to the fields of biocatalysis and biochemical engineering. The amino acid sequence of the oleic acid hydratase OhyA1 mutant provided by this invention is shown in SEQ ID No. 1. Compared with the parent enzyme, the OhyA1 mutant oleic acid hydratase of this invention exhibits a restructured active site due to the deletion of phenylalanine side chain benzene ring groups at two sites, leading to an increased substrate binding pocket volume and significantly improved catalytic efficiency for long-chain fatty acid substrates containing multiple double bonds (especially linoleic acid). The OhyA1 mutant oleic acid hydratase provided by this invention exhibits high specificity for oleic acid, catalyzing only the cis-9 double bond hydration reaction of oleic acid. The product is a single 10-hydroxy fatty acid, avoiding isomer formation. The product purity can reach over 95%, and the oleic acid conversion rate can reach over 85%, significantly superior to existing microbial transformation systems.

The application discloses a healthy brewing process of Maotai-flavor liquor based on microbial flora domestication technology and belongs to the technical field of liquor brewing. The method comprises the following steps: in the grain moistening process of the lower layer and the layer forming process, raw materials are subjected to graded acidification pretreatment by adopting a two-stage adding mode of lactic acid and citric acid, so as to promote the release of bound flavor precursors in the kaffir corn cortex; microbial samples are collected from the Maotai-flavor liquor brewing environment, and after enrichment culture, the samples are subjected to three-stage continuous subculture domestication in a culture medium containing gradient concentrations of carbon sources, gradient concentrations of ethanol, gradient concentrations of organic acids and gradient temperatures, so as to obtain domesticated bacterial liquid; the domesticated bacterial liquid is subjected to enlarged culture to obtain a functional enhanced bacterial agent, and the bacterial agent is added in batches before the pile fermentation and pit entry fermentation; through the synergistic effect of the precursor release and the microbial conversion, the application can significantly improve the content of base liquor flavoring substances, reduce the content of harmful by-products such as n-propanol, stably improve the liquor yield, and has high process integration degree and is easy to popularize and promote in the industry.

The application provides a method for analyzing migration and transformation rules of nitrogen and phosphorus in sewage resource utilization, and relates to the technical field of sewage resource utilization. The method comprises the following steps: synchronously sampling and measuring nitrogen and phosphorus concentrations from source chambers, medium chambers and receiving chambers at different depths, and calculating apparent permeation flux and adsorption retardation coefficient; taking the difference between apparent permeation fluxes of nitrate nitrogen in the presence and absence of an inhibitor unit as an in-situ nitrification rate representation value, taking the difference between apparent permeation fluxes of ammonium nitrogen as an in-situ mineralization rate representation value, and taking the ratio between the sum of the two and the total nitrogen apparent permeation flux as a biological transformation contribution index; finally, based on the indexes at different depths, a vertical distribution map is drawn, a biological transformation dominant area, an adsorption and fixation dominant area and a physical permeation dominant area are demarcated, and a partition control scheme is output, so as to realize quantitative separation of physical permeation, adsorption and fixation and microbial transformation contribution, and establish a partition precise control mechanism based on the dominant action type.