Cytochrome P450s (CYPs) are one of the largest distributed enzymes, which catalyze more than 20 different reactions. At present, there has been an increasing realization of the power of P450 biocatalysts for the industrial synthesis of pharmaceuticals, agrochemicals, bulk chemicals, food ingredients, etc. On the other hand, the conditions of industrial processes at high temperature, high-pressure or in chemical solvent require the enzymes, which catalyze the bioconversion, have a specific properties such as thermostability, chemical tolerance or barophilicity. Up to date, the number of thermostable P450s is limited. Nowadays, DNA-metagenome technique gives us a chance to catch novel genes and unique interesting enzymes from microbial community in certain ecology. In this paper, metagenomic DNA extracted from water samples from Binh Chau hot spring was sequenced using Illumila’s HiSeq platform and was analysed to mining putative genes encoding cytochrome P450. The sequencing generated 9.4 Gb of reads containing 156,093 putative ORFs, of these, 106,903 genes were annotated in NCBI non-redundant protein sequence database. Among all the ORFs were annotated, 68 putative ORFs encoding cytochrome P450 were found belong to 36 specific groups of cytochrome P450 protein family. Of these, the melting temperature (Tm) from thirty-six completed ORFs was predicted for a better understanding of thermodynamic stability.

The sedimentary environment characteristics in Mong Cai coastal area were assessed through pH, Eh, grain sizes, 226Ra, 210Pb, S‰, DO parameters. Mong Cai coastal area is mostly influenced by Ka Long river system that makes changes in the salinity, pH of water, pH and Eh of sediment, grain sizes, and sedimentation rates in the coastal area. There were six sediment types in the coastal area which were coarse sand, medium sand, fine sand, very fine sand, very coarse silt, and coarse silt. Fine sand was common in surface sediments; very fine sand was dominant in sediment core at Ka Long river mount; coarse silt and very coarse silt were common in sediment core at Mui Ngoc. The average sedimentation rate at the Ka Long river mouth (0.72 cm/year) was higher than that at the Mui Ngoc (0.27 cm/year). The sedimentary environment was divided into 3 groups, the first group was marine characteristics higher than the terrigenous characteristic, the second group was terrigenous characteristics higher than marine characteristics, and the third group was marine characteristics. In sediment cores showed 3 stages. In stage 1, distribution fine sand, very fine sand, and very coarse silt, from 52 to 80 cm at the Ka Long river mouth and from 40 to 52 cm at the Mui Ngoc. In stage 2, distribution of very coarse silt, coarse silt, from 38 to 52 cm (1947 - 1877) at Ka Long river mouth with sedimentation rate from 0.08 to 0.31 cm/year, at the Mui Ngoc from 12 to 40 cm (1944 (12 -14 cm)) with sedimentation rate of 0.09 cm/year. In stage 3, distribution very coarse silt, very fine sand, fine sand, from 0 to 38 cm (1919 - 1961) at the Ka Long river mouth with sedimentation rate of 0.34 - 1.62 cm/year, at the Mui Ngoc from 0 to 12 cm (2019 – 1966) with sedimentation rate of 0.07 - 0.51 cm/year.

Beneficial plant-growth-promoting bacteria (PGPB) have been reasonably applied to rescue crucial issue for agriculture by salinity soil. Observed most of PGPB was found in endophyte, rhizosphere and soil. Indole acetic acid (IAA)-producing bacteria could naturally stimulate and facilitate plant growth. The knowledge of IAA production and content of bacteria resident in the marine environment has been typically insufficient and limited to date. In recent years, unwarrantable intrusions of sea water have been enlarged in the Mekong River Delta of Vietnam, threatening productive rice fields, local fruits, and cash crops. Therefore, finding PGPB in the coastal regions in the Mekong River Delta as a creative resource for sustainable agriculture is necessary and is a prompt challenge. In this study, IAA-producing bacteria from coastal regions of Ben Tre and Tra Vinh Provinces were isolated and adequately identified. Out of 202 bacterial isolates, 10 isolates showed the possible ability to produce IAA from L-tryptophan. These 10 isolates were objectively evaluated the capacity to produce IAA under 5% (w/v) NaCl in King B and marine broths. The results revealed that IAA production decreased in 5% NaCl, even though bacterial growth increased. These 10 IAA-producing bacteria were classified at the species level, Marinobacter hydrocarbonoclasticus, M. pelagius, M. daepoensis, and Mameliella phaeodactyli by 16S rRNA gene analysis. The most IAA producer in King’s B broth, the isolate C7, was investigated in more detail. The isolate C7 produced the maximum IAA amount (192.2 ± 1.14 µg/ml) under the presence of 20 g/l yeast extract, 2 g/l of L-tryptophan and 1% NaCl. The isolate C7 was able to grow at 1–17% (w/v) NaCl (optimum, 4%), but not in the absence of NaCl, indicating it is a moderate halophilic bacteria. This study highlighted the considerable ability to produce IAA of marine bacteria, which could be thoughtfully considered to use naturally as biofertilizers to promote plant growth in saline intrusion lands.

BackgroundHarlequin ichthyosis (HI) is a severe rare genetic disease that mainly affects the skin. Neonates with this disease are born with thick skin and large diamond-shaped plates covering most of their bodies. Affected neonates lose the ability to control dehydration and regulate temperature and are more susceptible to infections. They also face respiratory failure and feeding problems. These clinical symptoms are factors associated with high mortality rates of neonates with HI. Until now, there are still no effective treatments for HI patients and most patients die in the newborn period. Mutation in the ABCA12 gene, which encodes an adenosine triphosphate-binding cassette (ABC) transporter, has been demonstrated as the major cause of HI.Case presentationIn this study, we report the case who is one infant that was born prematurely at 32 gestational weeks with the whole body covered with thick plate-like scales of skin. The infant was severely infected with mild edema, multiple cracked skins full of the body, yellow discharge, and necrosis of fingers and toes. The infant was suspected to be affected by HI. Whole exome sequencing (WES) was performed as a tool for detecting the novel mutation in one prematurely born Vietnam infant with HI phenotype. And after that, the mutation was confirmed by the Sanger sequencing method in the patient and the members of his family. In this case, one novel mutation c.6353C > G (p.S2118X, Hom) in the ABCA12 gene, was detected in the patient. The mutation has not been reported in any HI patients previously. This mutation was also found in a heterozygous state in the members of the patient's family, including his parents, an older brother, and an older sister who are no symptoms.ConclusionsIn this study, we identified a novel mutation in a Vietnamese patient with HI by whole exome sequencing. The results for the patient and the members of his family will be helpful in understanding the etiology of the disease, diagnosing carriers, assisting in genetic counseling, and emphasizing the need for DNA-based prenatal screening for families with a history of the disease.

Laccase (EC 1.10.3.2) is an enzyme belonging to the polyphenol oxidase groups, which plays an important role in the oxidation of a wide variety of aromatic substrates, such as lignin, phenol, polyamine, and aryl diamines, as well as a number of other phenolic compounds or inorganic ions in the presence of oxygen. Laccase is widely applied in many different fields, especially in the textile industry, dyeing, and environmental pollution treatment. In this study, we have successfully cloned and expressed cDNA coding for laccase from Pleurotus pulmonarius MPN18 (PpLac). cDNA corresponds to the gene laccase (size 1566 bp) was attached to pET 21a(+) vector and expressed in E. coli BL21, after that the enzyme was purified through HisTrapTM sp 5mL column. The purified PpLac had an activity of 899.8 U, a 74% yield with a purity of 15.2 -fold, and was tested by SDS-PAGE electrophoresis with a molecular weight of Mw = 55 kDa. Enzyme displayed optimal activity at 50 ºC and pH 4.0. Enzyme had optimal activity of 20-40 ºC after 120 min incubation and pH 4 after 6 h incubation. In future, the recombinant enzyme will be characterized for supplementation into enzyme cocktail in the treatment of lignocellulosic material.