A novel two-step fermentation process using a mixed-sugar medium mimicking microalgal hydrolysate has been proposed to avoid glucose repression and thus to maximize substrate utilization efficiency. When DagA, a β-agarase was produced in one step in the mixed-sugar medium by using a recombinant Streptomyces lividans, glucose was found to have negative effects on the consumption of the other sugars and DagA biosynthesis causing low substrate utilization efficiency and low DagA productivity. To overcome such difficulties, a new strategy of sequential substrate utilization was developed. In the first step, glucose was consumed by Saccharomyces cerevisiae together with galactose and mannose producing ethanol, after which DagA was produced from the remaining sugars of xylose, rhamnose and ribose. Fucose was not consumed. By adopting this two-step process, the overall substrate utilization efficiency was increased approximately 3-fold with a nearly 2-fold improvement of DagA production, let alone the additional benefit of ethanol production.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.biortech.2015.02.072 | DOI Listing |
Environ Microbiol
January 2025
Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa.
Plant detritus is abundant in grasslands but decomposes slowly and is relatively nutrient-poor, whereas animal carcasses are labile and nutrient-rich. Recent studies have demonstrated that labile nutrients from carcasses can significantly alter the long-term soil microbial function at an ecosystem scale. However, there is a paucity of knowledge on the functional and structural response and temporal scale of soil microbiomes beneath large herbivore carcasses.
View Article and Find Full Text PDFBiotechnol Bioeng
January 2025
Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, Minnesota, USA.
N-acyl l-homoserine lactones are signaling molecules used by numerous bacteria in quorum sensing. Some bacteria encode lactonases, which can inactivate these signals. Lactonases were reported to inhibit quorum sensing-dependent phenotypes, including virulence and biofilm.
View Article and Find Full Text PDFBiotechnol Biofuels Bioprod
January 2025
Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
Background: The climate crisis and depleting fossil fuel reserves have led to a drive for 'green' alternatives to the way we manufacture chemicals, and the formation of a bioeconomy that reduces our reliance on petrochemical-based feedstocks. Advances in Synthetic biology have provided the opportunity to engineer micro-organisms to produce compounds from renewable feedstocks, which could play a role in replacing traditional, petrochemical based, manufacturing routes. However, there are few examples of bio-manufactured products achieving commercialisation.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia.
This research presents the design and analysis of a compact metamaterial (MTM)-based star-shaped split-ring resonator (SRR) enclosed in a square, constructed on a cost-effective substrate for liquid chemical sensing applications. The designed structure has dimensions of 10 × 10 mm and is optimized for detecting adulteration in edible oils. When the sample holder is filled with different percentages of oil samples, the resonance frequency of the MTM-based SRR sensor shift significantly.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Centre for Conservation and Utilization of Blue Green Algae, Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India. Electronic address:
Polysaccharides, found universally in all living-species, exhibit diverse biochemical structures and play crucial roles in microorganisms, animals, and plants to defend against pathogens, environmental stress and climate-changing. Microbial exopolysaccharides are essential for cell adhesion and stress resilience and using them has notable advantages over synthetic polysaccharides. Exopolysaccharides have versatile structures and physicochemical properties, used in food systems, therapeutics, cosmetics, agriculture, and polymer industries.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!