Bacillus as Siderophore and Iron-bioremoval Bacteria

ome Bacillus strains can produce siderophore. Siderophore is a chelating agent for ferric iron as a response to low iron environment. Bacillus has ability as iron bioremoval. The aim of this research was to get siderophore Bacillus strain which could resist to iron and to know the ability of its bioremoval. This research used Bacillus isolated from Kalimas Surabaya ie: A6, DA11, and SS19. The strains were screened for siderophore bacteria in Fe-CAS agar medium. Ferric bioreduction was analysed on medium contained FeCl3.6H2O 50; 100; and 150 mg/L. Ferric bioremoval was measured by Atomic Absorption Spectroscopy method. Bacillus A6, DA11, and SS19 could produce siderophore and also stand to media containing 150 mg/L FeCl3.6H2O. Bacillus DA11 had the highest ability of ferric bioremoval, which was 26.841 mg/L from 33.365 mg/L concentration, with efficiency 80.5%

Bacillus based biocontrol on Brassica

Many bacterial strains have been shown to mediate protection to biotic stress and promote growth of plants. Different bacteria can mediate protection in different ways e.g. by inhibition, competition or increasing plant resistance. Examples of bacteria that mediate protection to plants include different Pseudomonas, Serratia and Bacillus strains. Bacillus strains have one major advantage toward other biocontrol strains and that is the ability to form spores that are resilient against chemicals and mechanical damage. I have studied the effect of four closely related Bacillus strains on plants in two different projects, one concerned with oilseed rape (Brassica napus) and the other using Arabidopsis thaliana to allow mechanistic studies of the interaction. The bacterial strains are all classified as Bacillus amyloliquefaciens. These bacterial strains have been tested for phenological effects on plants and for plant protection towards pathogens like Alternaria brassicae, Botrytis cinerea, Leptosphaeria maculans, and Verticillium longisporum. Production of antifungal compounds by the strains and the effects on the different pathogens were investigated. Two potential candidates for biocontrol were identified. Both Bacillus strains were found to provide significant protection of oilseed rape against the four pathogens. The effects of Bacillus treatment on the B. napus transcriptome were studied using the cDNA-AFLP technique. Bacillus priming had strong systemic effects on leaf transcripts but small effects on roots. This far 65 differentially expressed plant genes have been identified due to Bacillus treatment, of which many seem related to metabolism. The effect of Bacillus seed treatment has also been studied on Arabidopsis. Significant protection was achieved also here using the same two strains toward Alternaria and Leptosphaeria as well as Pseudomonas syringae as pathogens. Arabidopsis signalling mutant studies showed that functional jasmonic acid (JA) and ethylene (Et) signalling as well as Npr1 were needed for Bacillus biocontrol. Expression levels of marker genes depending on these signalling pathways showed no increase upon Bacillus treatment, while an increase of the JA dependent marker occurred after Bacillus treated plants were infected by P. syringae. Altogether, Bacillus primed biocontrol seems to be based on induced systemic resistance (ISR)

Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components

The experiments conducted to determine the heat resistance of Bacillus megaterium ATCC 6458 at 90 and 100 C were completed. Estimates from replicate experiments at eight percent relative humidities (less than 0.001 to 100% RH) for each temperature were computed. A Bacillus cereus strain with high heat resistance was cultured and the resistance determined in phosphate buffer (D sub 121.1 = 2.16 min and z = 8.7 C). The profile of the dry heat resistance of B. megaterium is summarized and the most resistant condition to the three spores (Bacillus subtilis var. niger, ATCC 29669, and Bacillus stearothermophilus, strain 1518) is compared

Isolation of a Novel Phage OTooleKemple52

A bacteriophage is a virus capable of infecting bacteria like ubiquitous soil-dwelling genus Bacillus. Within the Bacillus genus, there is the “ACT family” made up of B. thuringiensis, B. cereus, and B. anthracis, which are highly related but with different pathogenic characteristics. Because of this, phages isolated using a species in this group may have a broad host range encompassing several species from Bacillus. Since B. cereus and B. anthracis can result in fatal to mild sickness in humans, the non-pahtogenic B. thuringiensis kurstaki was used to discover and characterize novel phages. The phage OTooleKemple52 was isolated from a soil sample collected from Chesapeake, VA using “soil enrichment” to increase phage concentration and thus make detection more likely. A phage plaque was observed from this enrichment infection upon plating. The phage population was then purified until the morphology of the phage plaques was consistent (3 mm diameter with pinpoint clear centers). A large volume of phage stock (high titer lysate, HTL) was collected and was then used to obtain purified DNA for gel electrophoresis and genome sequencing. Additionally, an HTL sample was stained with 1% uranyl acetate and imaged using transmission electron microscopy to determine a myoviridae morphology with a head diameter of 80 nm and a tail length of 200 nm. The phage has a broad host range and was able to able to form plaques on 6 out of 8 Bacillus strains tested. The genome of the phage will be annotated and compared to other phage genomes. Through studying phages we can work to better understand both phage diversity and the interrelatedness of the Bacillus genus. The benefits of studying bacteriophages have reaches from environmental to medical significance because of the ubiquitous and pathogenic characteristics of the host bacteria.https://scholarscompass.vcu.edu/uresposters/1241/thumbnail.jp

Inhibition of growth and ochratoxin A production of Aspergillus carbonariu by Bacillus strains isolated from cocoa bean fermentation

Ivorian raw cocoa beans are recurrently subject to ochratoxin A (OTA) contamination. The use of chemical and physical means to reduce or prevent the OTA production in cocoa beans is prohibited or inefficient. The present study aimed to improve the sanitary quality of raw cocoa bean by determining the potential for biological control of fungal growth and OTA production of Aspergillus carbonarius using Bacillus sp strains isolated from fermented cocoa beans. Results of both direct and indirect tests carried out using the double layer agar technique showed seven (7) Bacillus strains with A. carbonarius growth inhibition abilities at up 50 %. In addition, inhibition of fungal growth tests in a liquid culture medium have revealed OTA production inhibition abilities of tested Bacillus strains, whether by the culture supernatant or the cell suspensions. The cell suspensions of strains BC35, BC46, BC52, BC53 and BC54 showed an important antagonistic effect to OTA production ranging from 78.7 to 95.8 %. However, only liquid culture supernatants of strains BC35, BC54 and BC46 recorded the best activities about 6.4, 48.4 and 70.0% respectively against to OTA production. Results suggest a direct or an indirect action via metabolites produced by tested Bacillus strains on A. carbonarius growth coupled probably with consumption and/or OTA binding. We could hope tested Bacillus strains could be a promising agent for biological control of growth and OTA production of A. carbonarius in raw cocoa beans during the post-harvest processing

Evaluating the capacity of human gut microorganisms to colonize the zebrafish larvae (Danio rerio)

Indexación: Scopus.In this study we evaluated if zebrafish larvae can be colonized by human gut microorganisms. We tested two strategies: (1) through transplantation of a human fecal microbiota and (2) by successively transplanting aerotolerant anaerobic microorganisms, similar to the colonization in the human intestine during early life. We used conventionally raised zebrafish larvae harboring their own aerobic microbiota to improve the colonization of anaerobic microorganisms. The results showed with the fecal transplant, that some members of the human gut microbiota were transferred to larvae. Bacillus, Roseburia, Prevotella, Oscillospira, one unclassified genus of the family Ruminococcaceae and Enterobacteriaceae were detected in 3 days post fertilization (dpf) larvae; however only Bacillus persisted to 7 dpf. Successive inoculation of Lactobacillus, Bifidobacterium and Clostridioides did not improve their colonization, compared to individual inoculation of each bacterial species. Interestingly, the sporulating bacteria Bacillus clausii and Clostridioides difficile were the most persistent microorganisms. Their endospores persisted at least 5 days after inoculating 3 dpf larvae. However, when 5 dpf larvae were inoculated, the proportion of vegetative cells in larvae increased, revealing proliferation of the inoculated bacteria and better colonization of the host. In conclusion, these results suggest that it is feasible to colonize zebrafish larvae with some human bacteria, such as C. difficile and Bacillus and open an interesting area to study interactions between these microorganisms and the host. © 2018 Valenzuela, Caruffo, Herrera, Medina, Coronado, Feijóo, Muñoz, Garrido, Troncoso, Figueroa, Toro, Reyes-Jara, Magne and Navarrete.https://www.frontiersin.org/articles/10.3389/fmicb.2018.01032/ful

Compounds produced by two robust Bacillus amyloliquefaciens biocontrol strains involved in antimicrobial activity and plant-growth promotion

Several members of the Bacillus genus are potential candidates to be used as biological control agents to combat pests or plant diseases. The bacterial attributes associated to Bacillus behaviour are mainly: the production of antimicrobial compounds, the plant-growth promotion capability and the induction of systemic resistance in plant host. In previous works, we have demonstrated this multifaceted biocontrol activity of B. amyloliquefaciens CECT8237 (UMAF6639) and CECT8238 (UMAF6614) strains, which contributes to plant protection against bacterial and fungal pathogens. In order to identify the bacterial features responsible for the outstanding biocontrol activity of these strains, their genomes were sequenced and analysed. Firstly, those features previously described for other Bacillus to be involved in the biocontrol activity were localized: i) Biosynthetic genes of secondary metabolites. Apart from the lipopeptides, formerly detected, we have demonstrated the production of other additional compounds that might participate in the antibiosis activity; ii) Biosynthetic genes of the volatile compounds 2,3-butanediol and acetoin, both involved in the induction of plant defence responses. Secondly, genetic singularities non-conserved within the Bacillus genus, which might contribute to the biocontrol ability of B. amyloliquefaciens CECT8237 and CECT8238 were identified in both genomes. Among them, we highlight two genomic regions hypothetically implicated in the production of non-characterized secondary metabolites. Ongoing studies are focused on elucidating the functionality of these uncharacterized regions, leading to a better understanding of the mechanisms of action involved in the robust biocontrol skills of these strains.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Effects of plant growth promoting rhizobacteria (PGPR) on yield,growth and nutrient contents in organically growing raspberry

During 2003 and 2005, plant growth promoting effects of two Bacillus strains OSU-142 (N2-fixing) and M3 (N2-fixing and phosphate solubilizing) were tested alone or in combinations on organically grown primocane fruiting raspberry (cv. Heritage) plants in terms of yield, growth, nutrient composition of leaves and variation of soil nutrient element composition in the province of Erzurum, Turkey. The results showed that Bacillus M3 treatment stimulated plant growth and resulted in significant yield increase. Inoculation of raspberry plant roots and rhizosphere with M3 and/or OSU-142 + M3, significantly increased yield (33.9% and 74.9%), cane length (13.6% and 15.0%), number of cluster per cane (25.4% and 28.7%) and number of berries per cane (25.1% and 36.0%) compared with the control, respectively. In addition, N, P and Ca contents of raspberry leaves with OSU-142 + M3 treatment, and Fe and Mn contents of the leaves of raspberry with M3 and OSU-142 + M3 applications significantly improved under organic growing conditions. Bacterial applications also significantly effected soil total N, available P, K, Ca, Mg, Fe, Mn, Zn contents and pH. Available P contents in soil was determined to be increased from 1.55 kg P2O5/da at the beginning of the study to 2.83 kg P2O5/da by OSU-142, to 5.36 kg P2O5/da by M3 and to 4.71 kg P2O5/da by OSU-142 + M3 treatments. The results of this study suggest that Bacillus M3 alone or in combination with Bacillus OSU-142 have the potential to increase the yield, growth and nutrition of raspberry plant under organic growing conditions