Isolation of acetic acid bacteria from honey

Four thermotolerant acetic acid bacteria designated as CMU1, CMU2, CMU3 and CMU4 were isolated from six honey samples produced by three native bee species in northern Thailand, namely the dwarf honey bee (Apis florea), Asian honey bee (A. cerena) and giant honey bee (A. dorsata). All isolates were tested for their tolerance to acetic acid and ethanol at 30C and 37C. It was found that they grew only in a medium containing 1% (v/v) acetic acid at 30C. However, isolate CMU4 showed the highest toleration to ethanol, viz. 10% (v/v) and 9% (v/v) at 30C and 37C respectively. Morphological and biochemical examination indicated that all isolates were members of the genus Gluconobacter

Plant and Microbes Interaction

บทคัดย่อ พืชและจุลินทรีย์มีรูปแบบความสัมพันธ์ทั้งที่เป็นประโยชน์ และก่อให้เกิดโทษกับต้นพืช การแบ่งกลุ่มของความสัมพันธ์ระหว่างพืชกับจุลินทรีย์อาจแบ่งได้เป็น แบบก่อโรค เช่น แบคทีเรีย ฟังไจ ไวรัส และไวรอยด์ที่เป็นสาเหตุของโรคพืช และจุลินทรีย์กลุ่มที่ให้ประโยชน์ต่อพืช เช่น  จุลินทรีย์บริเวณรอบรากพืช ที่สร้างสารส่งเสริมการเจริญเติบโตของพืช เพิ่มความสามารถในการใช้และดูดซึมแร่ธาตุ  และเพิ่มความต้านทานของพืชต่อความเครียดทั้งทางกายภาพและทางชีวภาพ แบคทีเรียเอนโดไฟต์ (bacterial endophyte)  บางชนิดที่มีความสามารถสร้างสารการส่งเสริมการเจริญเติบโตของพืชได้ หรือซิมไบโอส (symbiose) เช่น แบคทีเรียที่อาศัยอยู่ในรากพืชในจีนัส Rhizobium และ Frankia มีความสามารถในการตรึงไนโตรเจน และเปลี่ยนรูปให้ได้แอมโมเนียและไนเตรทที่พืชสามารถนำไปใช้ประโยชน์ได้ นอกจากนี้ยังมีราไมคอร์ไรซา (mycorrhizal fungi) ที่ช่วยเพิ่มพื้นที่ผิวและความสามารถในการดูดซับน้ำและแร่ธาตุอาหารในพืช และป้องกันรากพืชจากการเข้าทำลายของเชื้อโรค จากความรู้เหล่านี้ สารออกฤทธิ์ที่ผลิตจากจุลินทรีย์จึงถูกนำมาใช้เพื่อส่งเสริมการเจริญเติบโตของพืช หรือกระตุ้นการเจริญเติบโตของพืช เช่น ปุ๋ยชีวภาพ (biofertilizer) สารกลุ่มที่ใช้เป็นตัวกระตุ้นพืช (phytostimulator) หรืออาจใช้เป็นยาฆ่าแมลง (biopesticide) เพื่อควบคุมโรคพืช และเพิ่มผลผลิตทางการเกษตรได้   คำสำคัญ: ความสัมพันธ์ของพืชและจุลินทรีย์ จุลินทรีย์ส่งเสริมการเจริญเติบโตของพืช จุลินทรีย์ก่อโรคในพืช ABSTRACT Plant and microbes relationship can be beneficial and harmful to plants. The pattern of plant and microbes interaction can be either pathogenic or beneficial. Pathogenic microbes are bacteria, fungi, virus and viroid that can cause disease in host plant. Beneficial microbes, such as rhizospheric microbes that can produce plant growth promoters, increase nutrient acquisition and help plant to resist physiological and biochemical stress. Some endophytic bacteria can produce plant growth promoters. Some symbioses such as Rhizobium and Frankia can reduce nitrogen gas in the air into other form of nitrogen compounds. In addition, mycorrhizal fungi can increase absorption area of the root and water availability. Furthermore, they can help plant defense against pathogens. From these knowledges, bioactive compounds produced from microbes are widely used to stimulate plant growth in the form of biofertilizers, phytostimulators and biopesticides to control plant pathogen and increase crop yield.   Keywords: plant-microbes interaction, plant growth-promoting microorganism, pathoge

Cave Actinobacteria as Producers of Bioactive Metabolites

Recently, there is an urgent need for new drugs due to the emergence of drug resistant pathogenic microorganisms and new infectious diseases. Members of phylum Actinobacteria are promising source of bioactive compounds notably antibiotics. The search for such new compounds has shifted to extreme or underexplored environments to increase the possibility of discovery. Cave ecosystems have attracted interest of the research community because of their unique characteristics and the microbiome residing inside including actinobacteria. At the time of writing, 47 species in 30 genera of actinobacteria were reported from cave and cave related habitats. Novel and promising bioactive compounds have been isolated and characterized. This mini-review focuses on the diversity of cultivable actinobacteria in cave and cave-related environments, and their bioactive metabolites from 1999 to 2018

Deep-Sea Actinobacteria Mitigate Salinity Stress in Tomato Seedlings and Their Biosafety Testing

UThis research study was funded by the Spanish Ministry for Economy and Competitiveness and the European Union, within the context of the research project CGL2017-91737-EXP and by the Andalusian Regional Government and the European Union (research project P18-RT-976) and by the European Union through the Erasmus+ program and partially supported by Chiang Mai University. PR is grateful to the Graduate School, Chiang Mai University, for the TA/RA scholarship for 2019-2021.Soil salinity is an enormous problem affecting global agricultural productivity. Deep-sea actinobacteria are interesting due to their salt tolerance mechanisms. In the present study, we aim to determine the ability of deep-sea Dermacoccus (D. barathri MT2.1T and D. profundi MT2.2T) to promote tomato seedlings under 150 mM NaCl compared with the terrestrial strain D. nishinomiyaensis DSM20448T. All strains exhibit in vitro plant growth-promoting traits of indole-3-acetic acid production, phosphate solubilization, and siderophore production. Tomato seedlings inoculated with D. barathri MT2.1T showed higher growth parameters (shoot and root length, dry weight, and chlorophyll content) than non-inoculated tomato and the terrestrial strain under 150 mM NaCl. In addition, hydrogen peroxide (H2O2) in leaves of tomatoes inoculated with deep-sea Dermacoccus was lower than the control seedlings. This observation suggested that deep-sea Dermacoccus mitigated salt stress by reducing oxidative stress caused by hydrogen peroxide. D. barathri MT2.1T showed no harmful effects on Caenorhabditis elegans, Daphnia magna, Eisenia foetida, and Escherichia coli MC4100 in biosafety tests. This evidence suggests that D. barathri MT2.1T would be safe for use in the environment. Our results highlight the potential of deep-sea Dermacoccus as a plant growth promoter for tomatoes under salinity stress.Spanish Ministry for Economy and CompetitivenessEuropean Commission CGL2017-91737-EXP P18-RT-976Andalusian Regional GovernmentChiang Mai UniversityGraduate School, Chiang Mai UniversityEuropean Commissio

Verrucosispora fiedleri sp. nov., an actinomycete isolated from a fjord sediment which synthesizes proximicins

A novel filamentous actinobacterial organism, designated strain MG-37T, was isolated from a Norwegian fjord sediment and examined using a polyphasic taxonomic approach. The organism was determined to have chemotaxonomic and morphological properties consistent with its classification in the genus Verrucosispora and formed a distinct phyletic line in the Verrucosispora 16S rRNA gene tree. It was most closely related to Verrucosispora maris DSM 45365T (99.5 % 16S rRNA gene similarity) and Verrucosispora gifhornensis DSM 44337T (99.4 % 16S rRNA gene similarity) but was distinguished from these strains based on low levels of DNA:DNA relatedness (~56 and ~50 %, respectively). It was readily delineated from all of the type strains of Verrucosispora species based on a combination of phenotypic properties. Isolate MG-37T (=NCIMB 14794T = NRRL-B-24892T) should therefore be classified as the type strain of a novel species of Verrucosispora for which the name Verrucosispora fiedleri is proposed

Antibody-Binding Motif of Mimetic Peptides to V. cholerae O139 Lipopolysaccharide

ABSTRACT This study explores deduced amino acid sequences of mimetic peptides of Vibrio cholerae O139 epitopes in order to design specific antigens for use in diagnostic method. Mimetic peptides expressed on E. coli flagella were selected from a FliTrx random peptide library via the interaction with purified monoclonal antibody to V. cholerae O139. Inserted nucleotides encoding bound peptides were determined by PCR. Peptides from clones giving positive results were confirmed by Western blot analysis. Sixty-two positive E. coli colonies were obtained and nucleotide-sequenced. Inserted nucleotides were translated into amino acids. Fifty-six patterns of deduced amino acid sequences were obtained without a consensus sequence. Most sequences of mimetic peptides have amino acid motif as RXXR with approximate molecular weight of 1,700 to 2,000. Arginine and glycine occupy the highest percentage of amino acid composition

Enhancing teak (Tectona grandis) seedling growth by rhizosphere microbes: a sustainable way to optimize agroforestry

With its premium wood quality and resistance to pests, teak is a valuable tree species remarkably required for timber trading and agroforestry. The nursery stage of teak plantation needs critical care to warrant its long-term productivity. This study aimed to search for beneficial teak rhizosphere microbes and assess their teak-growth-promoting potentials during nursery stock preparation. Three teak rhizosphere/root-associated microbes, including two teak rhizobacteria (a nitrogen-fixing teak root endophyte-Agrobacterium sp. CGC-5 and a teak rhizosphere actinobacterium-Kitasatospora sp. TCM1-050) and an arbuscular mycorrhizal fungus (Claroideoglomus sp. PBT03), were isolated and used in this study. Both teak rhizobacteria could produce in vitro phytohormones (auxins) and catalase. With the pot-scale assessments, applying these rhizosphere microbes in the form of consortia offered better teak-growth-promoting activities than the individual applications, supported by significantly increased teak seedling biomass. Moreover, teak-growth-promoting roles of the arbuscular mycorrhizal fungus were highly dependent upon the support by other teak rhizobacteria. Based on our findings, establishing the synergistic interactions between beneficial rhizosphere microbes and teak roots was a promising sustainable strategy to enhance teak growth and development at the nursery stage and reduce chemical inputs in agroforestry

Two Antimycin A Analogues from Marine-Derived Actinomycete Streptomyces lusitanus

Two new antimycin A analogues, antimycin B1 and B2 (1–2), were isolated from a spent broth of a marine-derived bacterium, Streptomyces lusitanus. The structures of 1 and 2 were established on the basis of spectroscopic analyses and chemical methods. The isolated compounds were tested for their anti-bacterial potency. Compound 1 was found to be inactive against the bacteria Bacillus subtilis, Staphyloccocus aureus, and Loktanella hongkongensis. Compound 2 showed antibacterial activities against S. aureus and L. hongkongensis with MIC values of 32.0 and 8.0 μg/mL, respectively

Draft Genome Sequence of the Marine Streptomyces sp. Strain PP-C42, Isolated from the Baltic Sea

Streptomyces, a branch of aerobic Gram-positive bacteria represents the largest genus of actinobacteria. The streptomycetes are characterized by a complex secondary metabolism and produce over two-thirds of the clinically used natural antibiotics today. Here we report the draft genome sequence of a Streptomyces strain PP-C42 isolated from the marine environment. A subset of unique genes and gene clusters for diverse secondary metabolites as well as antimicrobial peptides (AMPs) could be identified from the genome, showing great promise as a source for novel bioactive compound

Draft Genome Sequence of the Marine Streptomyces sp. Strain PP-C42, Isolated from the Baltic Sea

Streptomyces, a branch of aerobic Gram-positive bacteria represents the largest genus of actinobacteria. The streptomycetes are characterized by a complex secondary metabolism and produce over two-thirds of the clinically used natural antibiotics today. Here we report the draft genome sequence of a Streptomyces strain PP-C42 isolated from the marine environment. A subset of unique genes and gene clusters for diverse secondary metabolites as well as antimicrobial peptides (AMPs) could be identified from the genome, showing great promise as a source for novel bioactive compound