Isolation and identification of indole acetic acid producing bacteria from the coasts of Ben Tre and Tra Vinh Provinces

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.

Tyrosinase inhibitors and insecticidal materials produced by Burkholderia cepacia using squid pen as the sole carbon and nitrogen source

[[abstract]]Reports of tyrosinase inhibitors from microorganisms are rare. A tyrosinase inhibitor- and insecticidal materials-producing bacterium, strain TKU026, was isolated from Taiwanese soil and identified as Burkholderia cepacia. Among the tested chitin-containing materials, squid pen best enhanced the production of tyrosinase inhibitors and insecticidal materials. The tyrosinase inhibitory activity (5000 U/mL) and insecticidal activity (81%) against Drosophila larvae was maximised after cultivation on 1% squid-pen containing medium for three days. The tyrosinase inhibitory activity persisted even when the culture was treated with acidic or alkaline conditions of pH 3 or 11. The activities of both tyrosinase inhibitors and insecticide remained at 100%, even after treatment at 100℃ for 30 min. The culture supernatant after three days of cultivation also showed antifungal activity against Aspergillus fumigatus and Fusarium oxysporum with maximal activities of 100% and 80%, respectively, but no antibacterial activity against Escherichia coli was observed. The tyrosinase inhibitors were assumed to be polyphenolic compounds according to the results of chromatography.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子版[[countrycodes]]NL

Prospects for Food Fermentation in South-East Asia, Topics From the Tropical Fermentation and Biotechnology Network at the End of the AsiFood Erasmus+Project

Fermentation has been used for centuries to produce food in South-East Asia and some foods of this region are famous in the whole world. However, in the twenty first century, issues like food safety and quality must be addressed in a world changing from local business to globalization. In Western countries, the answer to these questions has been made through hygienisation, generalization of the use of starters, specialization of agriculture and use of long-distance transportation. This may have resulted in a loss in the taste and typicity of the products, in an extensive use of antibiotics and other chemicals and eventually, in a loss in the confidence of consumers to the products. The challenges awaiting fermentation in South-East Asia are thus to improve safety and quality in a sustainable system producing tasty and typical fermented products and valorising by-products. At the end of the “AsiFood Erasmus+ project” (www.asifood.org), the goal of this paper is to present and discuss these challenges as addressed by the Tropical Fermentation Network, a group of researchers from universities, research centers and companies in Asia and Europe. This paper presents current actions and prospects on hygienic, environmental, sensorial and nutritional qualities of traditional fermented food including screening of functional bacteria and starters, food safety strategies, research for new antimicrobial compounds, development of more sustainable fermentations and valorisation of by-products. A specificity of this network is also the multidisciplinary approach dealing with microbiology, food, chemical, sensorial, and genetic analyses, biotechnology, food supply chain, consumers and ethnology

Calixarene-Based Molecules for Cation Recognition

This review discusses molecular design principles of calixarene-type macrocycles for ion recognition and gives examples on the relationship between structure and selectivity, however without attempting to cover all the different approaches

Calixarene-based molecules for cation recognition

Abstract: This review discusses molecular design principles of calixarene-type macrocycles for ion recognition and gives examples on the relationship between structure and selectivity, however without attempting to cover all the different approaches

An Son and the Neolithic of Southern Vietnam

Between 4500 and 3500 years ago, partially intrusive Neolithic populations in the riverine basins of mainland Southeast Asia began to form mounded settlements and to develop economies based on rice cultivation, fishing, hunting, and the domestication of animals, especially pigs and dogs. A number of these sites have been excavated in recent years and they are often large mounds that can attain several meters in depth, comprising successive layers of alluvial soil brought in periodically to serve as living floors. The site of An Son is of this type and lies in a small valley immediately north of the Mekong Delta in southern Vietnam. Excavated on five occasions since 1978, and most recently in 2009, it was occupied from the late third into the late second millennium b.c. An Son has produced evidence that attests the domestication of pigs and dogs in all layers apart (perhaps) from the most basal one, which was not investigated in 2009, together with the growing of rice of the subspecies Oryza sativa japonica, of Chinese Neolithic origin. The oldest pottery has simple incised and punctate zoned decoration with parallels in central Thailand, especially in the basal phases at Nong Nor and Khok Phanom Di. From its middle and later occupation phases (1800–1200 b.c.), An Son has produced a number of supine extended burials with finely decorated pottery grave goods that carry some unique forms, especially vessels with wavy or serrated rims. The An Son burials represent a Neolithic population that expressed a mixture of both indigenous Hoabinhian and more northerly (probably Neolithic southern Chinese) cranial and dental phenotypes, perhaps representing a likely ancestral population for some of the modern Austroasiatic speaking populations of mainland Southeast Asia

Ru Diep and the Quynh Van culture of central Vietnam

Excavations in 2015 at the site of Ru Diep in north-central Vietnam (Ha Tinh Province) raise significant questions about the transition into the Neolithic in this region, more than 5000 years ago. The material culture from the site reveals a mixture of both pre-Neolithic (Quynh Van culture) and Neolithic elements, in a shell mound context. The C14 dates for the site suggest that the surviving layers were deposited between outer limits of 3200 and 2900 cal. BC, but Bayesian analysis indicates a likely accumulation in less than 50 years. This date is almost one millennium older than expected for Neolithic-related materials in north-central Vietnam.The research of Peter Bellwood and Philip Piper was funded by ARC Discovery Project Grant No. 140100384

Novel Anti-Acetylcholinesterase Effect of <i>Euonymus laxiflorus</i> Champ. Extracts via Experimental and In Silico Studies

Alzheimer’s disease (AD) is the most common form of dementia, which is recorded as a global health issue. Natural acetylcholinesterase inhibitors (AChEIs) are considered a helpful therapy for the management of symptoms of patients with mild-to-moderate AD. This work aimed to investigate and characterize Euonymus laxiflorus Champ. (ELC) as a natural source of AChEIs compounds via in vitro and virtual studies. The screening parts used, including the leaves, heartwood, and trunk bark of ELC, revealed that the trunk bark extract possessed the highest activity, phenolics and flavonoid content. The in vitro anti-Alzheimer activity of ELC trunk bark was notably reclaimed for the first time with comparable effect (IC50 = 0.332 mg/mL) as that of a commercial AChEI, berberine chloride (IC50 = 0.314 mg/mL). Among various solvents, methanol was the most suitable to extract ELC trunk bark with the highest activity. Twenty-one secondary metabolites (1–21) were identified from ELC trunk bark extract, based on GCMS and UHPLC analyses. Of these, 10 volatile compounds were identified from this herbal extract for the first time. One phenolic (11) and seven flavonoid compounds (15–21) were also newly found in this herbal extract. Of the identified compounds, chlorogenic acid (11), epigallocatechin gallate (12), epicatechin (13), apigetrin (18), and quercetin (20) were major compounds with a significant content of 395.8–2481.5 μg/g of dried extract. According to docking-based simulation, compounds (11–19, and 21) demonstrated more effective inhibitory activity than berberine chloride, with good binding energy (DS values: −12.3 to −14.4 kcal/mol) and acceptable RMSD values (0.77–1.75 Å). In general, these identified compounds processed drug properties and were non-toxic for human use, based on Lipinski’s rule of five and ADMET analyses