Bacteriophage T4 lysis and lysis inhibition: molecular basis of an ancient story

T4 requires two proteins: holin, T (lesion formation and lysis timing) and endolysin, E (cell wall degradation) to lyse the host at the end of its life cycle. E is a cytoplasmic protein that sequestered away from its substrate, but the inner membrane lesion formed by T allows E to gain access to the cell wall. T4 exhibits lysis inhibition (LIN), a phenomenon in which a second T4 infection occurs ≤ 3 min after primary infection results a delay in lysis. Mutations that abolish LIN mapped to several genes but only rV encoding the holin, T, and rI, encoding the antiholin, RI, are required for LIN in all hosts which support T4 replication. Antiholin RI inhibits T-mediated lysis by direct interaction with the holin. T has at least one transmembrane domain with its Nterminus (TNTD) in the cytoplasm and C-terminus in the periplasm (TCTD). In contrast, the N-terminus of RI (RINTD) is predicted to function as a cleavable signal sequence allowing the secretion of the RI C-terminal domain (RICTD) into the periplasm. Most of RI mutations which abolish LIN occur in the RICTD, suggesting RI inhibits T-mediated lysis by interacting with T via RICTD. Topological analysis of RI and T showed that fusion of PhoA signal sequence (ssPhoA) to RICTD is necessary and sufficient for LIN and ssPhoAΦTCTD interferes with RI-mediated LIN, indicating T and RI interact via periplasmic C-terminal domains. In T4 infection, LIN is observed only when superinfection takes place, indicating either the antiholin or the LIN signal must be unstable. Both RI and RINTDΦPhoA are localized to both the inner membrane and the periplasm suggesting that the RINTD is a Signal-Anchor-Release (SAR) domain. Protein stability studies indicated that the SAR domain is the proteolytic determinant of RI, and DegP is the protease that is responsible for RI degradation. To date, how TNTD participates in lysis and LIN is not known. Modifications and deletion of the N-terminus of T change the lysis time, indicating this domain is involved the in timing of lysis. GFP fusion to holin T allowed microscopic visualization of fluorescent patches on the membrane at the time of lysis

Income diversification and poverty in the Northern Uplands of Vietnam:

Poverty, income diversification,

Optimization of culture conditions of Streptomyces antibioticus strain 1083 to improve the antimicrobial activity against Aeromonas hydrophila

Fish is a healthy, high protein and low fat food that encourages the health and growth of people, especially children. However, in fact fish is very sensitive to many diseases which affects the productivity and quality of fish. Therefore, identifying the cause of the diseases and finding preventive measures become an urgent task today. In the previous study, we isolated Streptomyces antibioticus strain 1083 that has the ability to antagonize Aeromonas hydrophila - a pathogenic bacterium in fish. Based on the obtained results, we continue to perform this study to determine optimal conditions for the culture of S. antibioticus strain 1083 in order to produce antimicrobial compounds against A. hydrophila. The production of antagonists by the strain 1083 was optimized by controlling the condition of different inoculations such as media, pH, temperature and incubation period. The results indicated that International Streptomyces Project 2 (ISP2) was the best medium for S. antibioticus strain 1083 to produce the highest antimicrobial activity against A. hydrophila with 32 mm in diameter of inhibited zone. The actinomycete strain 1083 could express the maximum antimicrobial activity when they were incubated in shaker incubator (200rpm) at 40oC with pH8 in 8 days. The ability of the actinomycete strain in antagonism against A. hydrophila was evaluated by adding different culture medium volume of S. antibioticus strain 1083. With adding 10% cultured solution volume of S. antibioticus strain 1083 into the culture medium of A. hydrophila, after 1 day of inoculation the number of pathogenic bacteria cells were completely eliminated

Effects of protein levels of commercial diets on the growth performance and survival rate of rabbitfish (Siganus guttatus) at the nursing stage

This study aimed to determine the effect of a commercial diet's protein level on the fry-to-fingerling stage. Thirty days-old fries having the initial length and weight of 18.25 ± 0.15 mm fish-1 and 0.036 ± 0.50 g fish-1 respectively have been used in this study. Diet having three protein levels i.e. 30% (trial 1 as control), 35% (trial 2), 40% (trial 3), and 45% (trial 4), respectively, have been used to evaluate the effect of protein, and each trial has been repeated three times. During the study, stocking density was allocated to 1000 fish per composite tank with a volume of 1 m3. After 30 days of rearing, the weight of fingerlings in trial 1 reached up to 1.50 ± 0.02 g fish-1 and it was recorded as 1.52 ± 0.01g for trial 2, these two were lower than that of trials 3 and 4, where fingerling weight was reported 1.69 ± 0.01 and 1.58g fish-1 respectively and obtained the best weight compared to others. The length of fingerlings at the end of the experimental period was also changed in different trials and it was recorded 47.12; 46.92; 50.97; and 48.89 mm fish-1 for trail 1, 2, 3, and 4 respectively, among the tested combinations lower fingerlings length was recorded for trial 2 (35% CP), but it is not significantly different for trial 1 and 2 and a significant difference (P < 0.05) was reported for trail 2, 3, and 4. The survival rate of fingerlings ranged from 67.27 to 72.33%. Meanwhile, the herd distribution coefficient variation (CVW) in the treatment using 40% protein (trial 3) was the highest at 72.33% (p < 0.05). The results of the study can be concluded that the level of protein has a significant effect on the various growth parameters of fingerlings

A multi locus sequence analysis scheme for phylogeny of the Bacillus subtilis species complex and its advantages over 16S rRNA genes

A multi locus sequence analysis (MLSA approach) was studied on the Bacillus genus, or the Bacillus subtilis species complex for specific, including 08 strains from four species (B. subtilis, B. pumilus, B. licheniformis and B. amyloliquefaciens) were provided by Biotechnology Center of Ho Chi Minh City. The research was based on sequences of 16S rRNA genes, the concatenation of five protein-coding housekeeping genes: glpF, pta, purH, pycA, and rpoD. After PCR amplification and sequencing the phylogenetic tree of 16S rRNA sequences, concatenate sequences (as well as the phylogenetic tree of each housekeeping gene) are constructed for comparison and discussion. The aim of this study is reach for better resolution and differentiation of strains and species within the B. subtilis species and to determine whether MLSA scheme show advantages in 16S rRNA gene-based studies

Bringing social and cultural considerations into environmental management for vulnerable coastal communities: Responses to environmental change in Xuan Thuy National Park, Nam Dinh Province, Vietnam

This paper elaborates the importance of considering social and cultural factors within management responses to environmental change in coastal areas. The case study taken is Xuan Thuy National Park in Nam Dinh Province, Vietnam. This is a marginalised coastal area where rising sea levels, increasing storm surges and saltwater intrusion place pressure on coastal ecosystems, yet where communities continue to rely on these same ecosystems for agriculture- and aquaculture-related livelihoods. We interview stakeholders in Xuan Thuy National Park, connecting these with a narrative review of existing research into social and environmental change in the park to understand research gaps and challenges for vulnerable coastal areas like the Nam Dinh coast. Based on our findings, we suggest that whilst the effects of a changing environment on physical health and economic activity are increasingly well understood, effects on wellbeing and social relations can be even more immediate and profound in daily living. In turn, we argue environmental management has a crucial role to play not only for ecosystem-based adaptation, but also in sustaining wellbeing and allowing culturally meaningful practices to continue – especially in coastal regions where changes can be even more intense and immediate. However, we caution that whilst techno-scientific solutions grounded in environmental management do have significant potential in reducing impacts of extreme events and slower-onset environmental changes, they must not divert attention away from structural issues that can make some people or areas more vulnerable in the first instance

Cyanide detoxification efficiency of injection and soak of hydroxocobalamin, sodium nitrite and sodium thiosulfate for sea water ornamental fish

The Oceanographic Museum offers interesting exhibits of several marine lives for tourist sightseeing and entertainment. These sea water ornamental fish are all caught in the wild. However, its health can be affected by cyanide poisoning during human fishing. Depending on the level of cyanide poisoning, fish can die after one and two weeks that caused economic damages for the museum. The present study is concerned with results of cyanide detoxification by using direct injection into cinnamon clownfish or soak of hydroxocobalamin, sodium nitrite and sodium thiosulfate with the aim of improving the health, survival and life time for fish, contributing to increasing economic efficiency for the Oceanographic Museum

COPPER HEXACYANOFERRATE (II): SYNTHESIS, CHARACTERIZATION, AND CESIUM, STRONTIUM ADSORBENT APPLICATION

Low-cost nanoscale copper hexacyanoferrate (CuHF), a good selective adsorbent for cesium (Cs+) removal, was prepared using the chemical co-precipitation method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy (HR-TEM) were conducted to determine the CuHF morphology. Copper hexacyanoferrate, Cu13[Fe(CN)6]14.(2K).10H2O, has a cubic structure (space group F-43m) in the range of 10-30 nm and a Brunauer-Emmett-Teller (BET) surface area of 462.42 m2/g. The removal of Cs+ and Sr2+ is dependent on pH; the maximum adsorption capacity (qmax) of CuHF is achieved at a pH = 6. From the Langmuir model, qmax = 143.95 mg/g for Cs+ and 79.26 mg/g for Sr2+, respectively. At high concentrations, Na+, Ca2+, and K+ ions have very little effect on Cs+ removal, and Na+ and K+ ions have a higher affinity for removing Sr2+ than Ca2+ at all concentrations. CuHF has a high affinity for alkaline cations in the order: Cs+ > K+ > Na+ > Ca2+ > Sr2+, as proposed and discussed

Isolation and characterization of Rhizobium spp. and Bradyrhizobium spp. from legume nodules

Rhizobia topic has been re-focused in recent years because of new findings on their traits not only as nitrogen-fixing bacteria but also as plant growth-promoting rhizobacteria. When combing rhizobial strains with novel biological carriers (e.g., biochar) for inoculant production, it brings great potential for improving soil health in long-term. Appreciating this trend, this study is designed to isolate and characterize local rhizobial strains from legume fields using the conventional method with some modifications to increase efficiency in rhizobial identification. As a result, 17 rhizobial strains were isolated and classified biochemically that genetic identification outcome confirmed 10 strains belong to 07 different Rhizobium species as R. mayense, R. paknamense, R. pusense, R. miluonense, R. tropici, R. phaseoli, and R. multihospitium while the rest belong to 06 various Bradyrhizobium species as B. elkanii, B. centrosematis, B. guangxiense, B. liaoningense, B. yuanmingense, and B. arachidis. Thermal and saline tolerant tests together with seed germination tests also performed on these rhizobial strains to gain data on their responses to abiotic stresses. By comparing rice and mung bean GI values, we can assess the effectiveness of each rhizobial strains to help seeds at their early germination