scholarly journals Physiology and Nutrition of Treponema primitia, an H2/ CO2-Acetogenic Spirochete from Termite Hindguts

2004 ◽  
Vol 70 (3) ◽  
pp. 1307-1314 ◽  
Author(s):  
Joseph R. Graber ◽  
John A. Breznak

ABSTRACT Treponema primitia strains ZAS-1 and ZAS-2, the first spirochetes to be isolated from termite hindguts (J. R. Leadbetter, T. M. Schmidt, J. R. Graber, and J. A. Breznak, Science 283:686-689, 1999), were examined for nutritional, physiological, and biochemical properties relevant to growth and survival in their natural habitat. In addition to using H2 plus CO2 as substrates, these strains were capable of homoacetogenic growth on mono- and disaccharides and (in the case of ZAS-2) methoxylated benzenoids. Cells were also capable of mixotrophic growth (i.e., simultaneous utilization of H2 and organic substrates). Cell extracts of T. primitia possessed enzyme activities of the Wood/Ljungdahl (acetyl coenzyme A) pathway of acetogenesis, including tetrahydrofolate-dependent enzymes of the methyl group-forming branch. However, a folate compound was required in the medium for growth. ZAS-1 and ZAS-2 growing on H2 plus CO2 displayed H2 thresholds of 650 and 490 ppmv, respectively. Anoxic cultures of ZAS-1 and ZAS-2 maintained growth after the addition of as much as 0.5% (vol/vol) O2 to the headspace atmosphere. Cell extracts exhibited NADH and NADPH peroxidase and NADH oxidase activities but neither catalase nor superoxide dismutase activity. Results indicate that (i) T. primitia is able to exploit a variety of substrates derived from the food of its termite hosts and in so doing contributes to termite nutrition via acetogenesis, (ii) in situ growth of T. primitia is likely dependent on secretion of a folate compound(s) by other members of the gut microbiota, and (iii) cells possess enzymatic adaptations to oxidative stress, which is likely to be encountered in peripheral regions of the termite hindgut.

2007 ◽  
Vol 57 (3) ◽  
pp. 616-619 ◽  
Author(s):  
Maria Sizova ◽  
Nicolai Panikov

Psychrotolerant (0–25 °C), chemolithotrophic Gram-negative cocci were isolated from Alaskan forest soil. The novel isolate was found to grow autotrophically on H2 : CO2 mixtures and to switch to heterotrophic growth on media containing organic substrates. The novel strain utilized a wide range of organic acids, some simple sugars and alcohols. Naphthalene vapour did not support growth. On the basis of 16S rRNA gene sequence similarity, the novel strain is affiliated to the genus Polaromonas, of the class Betaproteobacteria, and is related to Polaromonas naphthalenivorans (99.6 % gene sequence similarity), Polaromonas aquatica (97.4 %) and Polaromonas vacuolata (96.1 %). The membrane phospholipids contained 16 : 1ω7c/16 : 1ω6c, 16 : 0 and 18 : 1ω7c, similar to the fatty acids found for P. naphthalenivorans, P. aquatica and P. vacuolata. On the basis of DNA–DNA hybridization, physiological and biochemical properties, the hydrogen-oxidizing mixotrophic isolate represents a novel species, for which the name Polaromonas hydrogenivorans sp. nov. is proposed. The type strain is DSM 17735T (=NRRL B-41369T).


2018 ◽  
Vol 28 ◽  
pp. 17-26 ◽  
Author(s):  
S.M. Derkach ◽  
M.V. Miahka ◽  
V.V. Volkohon ◽  
L.T. Nakonechna ◽  
S.B. Dimova ◽  
...  

Objective. Screen the active cellulolytic strains of Trichoderma micromycetes, investigate their morphological and cultural, physiological and biochemical properties for further use in the composting of organic substrates as a straw destroyer.  Methods. Microbiological, biochemical, statistical. Results. 150 isolates of cellulolytic microscopic fungi of the genus Trichoderma were obtained from semi-decomposed straw. Among isolated fungi, the most active influence on the destruction of cellulose is typical for the association of micromycetes Trichoderma sp. 128. The components of the association (Trichoderma sp. 128/1 and Trichoderma sp. 128/2, respectively) differ in their nature of growth in the digest medium, colouring of colonies, and cellulolytic activity. Under simultaneous cultivation of the association components in a medium where the only source of carbon is filter paper or straw, higher effect was observed compared with than their separate cultivation. The selected association provides a degree of straw decomposition of up to 33 % over a period of 21 days, which exceeds the activity of the known cellulolytic strain Trichoderma harzianum F-2455. By morphological and cultural, physiological and biochemical properties, the components of the fungal association have been identified as Trichoderma harzianum 128/1 and T. harzianum 128/2 (association – Trichoderma harzianum 128, respectively). Under the study of virulence of microorganisms on the model of white mice, it was established that the association components are not pathogenic for warm-blooded animals, which allows the association to be used in the production. Conclusion. Active cellulolytic association of micromycetes which includes two strains has been selected. The association is identified as Trichoderma harzianum 128. The use of the association of micromycetes can be promising when composting organic matter, in order to accelerate its mineralization.  


2021 ◽  
Vol 11 (6) ◽  
pp. 20-29
Author(s):  
Fetoon M ◽  
helaiwi Alk ◽  
Ismet Ara ◽  
Nadine Moubayed

Streptomyces are the most popular among the Actinomycetes groups and found in soils worldwide. They form an important part of the soil ecology within the Actinomycetales order. Streptomyces are diverse as secondary antibiotic metabolites such as Novobiocin, Amphotericin, Vancomycin, Neomycin, Gentamicin, Chloramphenicol, Tetracycline, Erythromycin and Nystatin. Thus, the current study was aimed to isolate, identify and assess the active antibiotic metabolites produced by different actinomyces sp. found in Saudi Arabian soils. Six samples were collected from desert soils of the Al Thumamah area and analyzed using GS-MS. Scanning Electron Microscopy was used to identify the bacterial strains along with their antibiotic metabolites effectiveness of secondary metabolites (antibiotics) against different Gram-positive (Bacillus subtilis, Staphylococcus aureus), negative pathogens (Pseudomonas aeruginosa, Escherichia coli, Salmonella suis, and Shigella sonnei) as well as the fungal strain Candida albicans was investigated. Thirty active bacterial (F1-30) strains were isolated from the soil samples and the strains F3, F7, F22, F30 have white, gray, pink, yellow and red colours respectively. Only ten strains (F13, F14, F15, F16, FI7, F18, F19, F20, F21, and F22) were found to have antimicrobial activity against at least one pathogen. The optimum growth environment was pH 4-10, temperature (300C), and NaCl (7% w/v) concentration. According to our findings, the extreme desert environment of Al Thumamah from Saudi Arabia is rich in its actinobacterial population with diverse colouring groups and various physiological and biochemical properties. This shows it’s capability of generating secondary metabolite elements that could inhibit pathogenic microorganisms.


2007 ◽  
Vol 57 (12) ◽  
pp. 2946-2951 ◽  
Author(s):  
Shams Tabrez Khan ◽  
Yukiyo Fukunaga ◽  
Yasuyoshi Nakagawa ◽  
Shigeaki Harayama

Two strains, MKG-38T and FYK2402M69T, were isolated from a marine sediment sample and a sea snail, respectively, both collected on the Pacific coast of Japan. Phylogeny of these new isolates based on 16S rRNA gene sequences indicated that they are members of the genus Lewinella. Morphological, physiological and biochemical properties of these two isolates, together with the type strains of the three previously described species of the genus Lewinella, were characterized. The new isolates were Gram-negative, aerobic, rod-shaped, chemo-organotrophic and able to degrade starch and CM-cellulose. A comparative polyphasic study showed that these two isolates represent two novel species of the genus Lewinella, for which the names Lewinella marina sp. nov. (type strain, MKG-38T=NBRC 102633T=NCIMB 14312T) and Lewinella lutea sp. nov. (type strain, FYK2402M69T=NBRC 102634T=NCIMB 14313T) are proposed. Emended descriptions of the genus Lewinella (Sly et al. 1998) and of Lewinella cohaerens, Lewinella nigricans and Lewinella persica are also proposed.


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