Improvement of bioethanol productivity of immobilized Saccharomyces bayanus with using sodium alginate-graft-poly(N-vinyl-2-pyrrolidone) matrix

State-of-the-art strategies and research advances for the biosynthesis of D-amino acids

D-amino acids (D-AAs) are the enantiomeric counterparts of L-amino acids (L-AAs) and important functional factors with a wide variety of physiological activities and applications in the food manufacture industry. Some D-AAs, such as D-Ala, D-Leu, and D-Phe, have been favored by consumers as sweeteners and fragrances because of their unique flavor. The biosynthesis of D-AAs has attracted much attention in recent years due to their unique advantages. In this review, we comprehensively analyze the structure-function relationships, biosynthesis pathways, multi-enzyme cascade and whole-cell catalysis for the production of D-AAs. The state-of-the-art strategies, including immobilization, protein engineering, and high-throughput screening, are summarized. Future challenges and perspectives of strategies-driven by bioinformatics technologies and smart computing technologies, as well as enzyme immobilization, are also discussed. These new approaches will promote the commercial production and application of D-AAs in the food industry by optimizing the key enzymes for industrial biocatalysts.

Microbicides for the Treatment of Sexually Transmitted HIV Infections

Approximately 34 million people were living with human immunodeficiency virus (HIV-1) at the end of 2011. From the last two decades, researchers are actively involved in the development of an effective HIV-1 treatment, but the results intended are still doubtful about the eradication of HIV. The HIV-1 virus has gone from being an "inherently untreatable" infectious agent to the one liable to be affected by a range of approved therapies. Candidate microbicides have been developed to target specific steps in the process of viral transmission. Microbicides are self-administered agents that can be applied to vaginal or rectal mucosal surfaces with the aim of preventing, or reducing, the transmission of sexually transmitted infections (STIs) including HIV-1. The development of efficient, widely available, and low-cost microbicides to prevent sexually transmitted HIV infections should be given high priority. In this review, we studied the various forms of microbicides, their mechanism of action, and their abundant approaches to control the transmission of sexually transmitted infections (STIs).