Novel microbial fermentation for the preparation of iron-chelating scallop skirts peptides-its profile, identification, and possible binding mode.

Iron chelating peptides have been widely utilized as iron supplements due to their excellent absorption capacity, However, the high cost and cumbersome manufacturing process of these peptides significantly limit their industrial application. In this study, fermentation was used for the first time to prepare iron chelating peptides. Bacillus altitudinis 3*1-3 was selected as the most suitable strain from 50 strains. The hydrolysates of fermented scallop skirts showed excellent iron-chelating capacity (9.39 mg/g). Aspartic acid, glutamic acid, and histidine are crucial for the binding of peptides to ferrous ions. The heptapeptide (FEDPEFE) forms six binding bonds with ferrous irons. Compared with ferrous sulfate, peptide-ferrous chelate showed more stability in salt solution and simulated gastrointestinal juice (p < 0.05). Furthermore, the fermentation method could save >50% of the cost compared with the enzymatic method. The results can provide a theoretical basis for the preparation of ferrous-chelated peptides using the fermentation method.

[A new approach for optimizing empirical prescriptions of famous physicians based on network target: taking Qingluo Decoction as an example].

Based on the network target approach and technology, this study proposed for the first time a novel optimization method for Chinese medicine formulae. Moreover, with Qingluo Decoction as an example, a method for the research and development of Chinese medicine, which combines scientific methodology and experience of famous doctors, was developed. Specifically, based on the composition of Qingluo Decoction, this study used the using network target for intelligent and quantitative analysis on drug actions(UNIQ) to predict the medicinals that targeted the key pathways of rheumatoid arthritis(RA) such as angiogenesis. Then, combining the experience of the first national Chinese medical master LI Ji-ren and Aihui famous Chinese medicine doctor LI Yan and Chinese medicine theory, this study developed a novel angiogenesis-targeted prescription modified Qingluo Decoction(MQLD). Afterward, the clinical efficacy and mechanism of MQLD were verified. The results showed that 27 medicinals with significant regulatory effect on angiogenesis-related key signaling pathways were identified by UNIQ, among which 6 were selected by the Chinese medicine physicians to develop the MQLD. Clinical trials demonstrated that the clinical efficacy of MQLD, in terms of either American College of Rheumatology 20% improvement and 50% improvement criteria(ACR20, ACR50) or TCM syndrome evaluation, was better than that of Qingluo Decoction. Experimental study revealed that MQLD can inhibit RA angiogenesis by acting on the vascular endothelial growth factor(VEGF) pathway, nuclear factor κB(NF-κB) pathway, inflammatory cytokine release, and immune cell regulation. Taken together, this study developed a new formula MQLD with improved clinical efficacy, precise applicable clinical settings, and authorized patent through the network target technology, thus providing a new way for the precise development of Chinese medicine and preservation of the experience of famous physicians.

Genetic Engineering Production of Ethyl Carbamate Hydrolase and Its Application in Degrading Ethyl Carbamate in Chinese Liquor.

Ethyl carbamate (EC), classified as a Group 2A carcinogen, is most abundant in the fermented foods, such as Cachaca, Shaoxing wine, and Chinese liquor (baijiu). Although biodegradation can reduce its concentration, a high ethanol concentration and acidic environment often limit its degradation. In the present study, a novel ethyl carbamate hydrolase (ECH) with high specificity to EC was isolated from Acinetobacter calcoaceticus, and its enzymatic properties and EC degradability were investigated. ECH was immobilized to resist extreme environmental conditions, and the flavor substance changes were explored by gas chromatography-mass spectrometry (GC/MS). The specific enzymatic activity of ECH was 68.31 U/mg. Notably, ECH exhibited excellent thermal stability and tolerance to sodium chloride and high ethanol concentration (remaining at 40% activity in 60% (v/v) ethanol, 1 h). The treatment of immobilized ECH for 12 h decreased the EC concentration in liquor by 71.6 µg/L. Furthermore, the immobilized ECH exerted less effect on its activity and on the flavor substances, which could be easily filtrated during industrial production.

Effects of flavourzyme addition on physicochemical properties, volatile compound components and microbial community succession of Suanzhayu.

Flavourzyme is known to promote protein decomposition, resulting in more peptides and amino acids which can improve the quality of fermented foods. In this study, the effects of flavourzyme addition on the fermentation of Suanzhayu fish were investigated. The results showed that the addition of 50 U/g flavourzyme reduced the water activity (aw) of products and promoted the release of trichloroacetic acid (TCA)-soluble peptides and free amino acids (FAAs). Thus, the stability of the product was improved and its nutritional value was increased. In addition, with the addition of flavourzyme, Lactobacillus and Saccharomyces more quickly became the dominant genera in the fermentation. Furthermore, the formation of alcohols, aldehydes, and esters was promoted in flavourzyme addition group. Redundant analysis (RDA) indicated that Lactobacillus and Lactococcus play important roles in the formation of flavors, especially for the characteristic flavors of Suanzhayu. Flavourzyme addition may be a novel method to greatly improve the properties of Suanzhayu and shorten the fermentation time.

Omics-prediction of bioactive peptides from the edible cyanobacterium Arthrospira platensis proteome.

BACKGROUND: Bioinformatics approaches are widely used to evaluate the prospects of novel protein sources in bioactive peptide research. Edible cyanobacteria are considered as potential protein precursors. However, the abundance of unicellular cyanobacterial proteins is largely unknown and highly dynamic according to the cultivation conditions, which need to be considered in this research field. The objective of this work was to evaluate the protein abundance of Arthrospira platensis, as well as to map the bioactive peptide sequences from the high-abundance proteins of the A. platensis proteome. RESULTS: The high-abundance proteins of the A. platensis proteome were identified with a high-performance liquid chromatography-tandem mass spectrometry-based method. A total of 593 proteins were detected and quantified. The occurrence frequency of the bioactive peptides in A. platensis proteome was calculated according to the amino acid sequences via the bioinformatics approaches. Further in silico digested by trypsin, pepsin and chymotrypsin, these proteins liberated 78, 99, and 96 bioactive peptides, respectively. In each case, angiotensin-converting enzyme inhibitors and dipeptidyl peptidase IV inhibitors were enriched. CONCLUSION: This work will help rationally design the protocols for cyanobacterial cultivation, protein pre-treatment and peptide separation, and further produce more peptides with specific functions. © 2017 Society of Chemical Industry.