Effects of Mineral Salts on the Activity and Composition of a Mixed Culture of Acidophilic Microorganisms

Microbiology ◽  
2021 ◽  
Vol 90 (6) ◽  
pp. 857-867
Author(s):  
J. Li ◽  
H. Yang ◽  
L. Tong ◽  
Z. Liu ◽  
Z. Jin ◽  
...  
2001 ◽  
Vol 67 (2) ◽  
pp. 821-826 ◽  
Author(s):  
David C. Bressler ◽  
Phillip M. Fedorak

ABSTRACT 3-Hydroxy-2-formylbenzothiophene (HFBT) is a metabolite found in many bacterial cultures that degrade dibenzothiophene (DBT) via the Kodama pathway. The fate of HFBT in cultures and in the environment is unknown. In this study, HFBT was produced by a DBT-degrading bacterium and purified by sublimation. When stored in organic solvent or as a crystal, the HFBT slowly decomposed, yielding colored products. Two of these were identified as thioindigo and cis-thioindigo. The supernatant of the DBT-degrading culture contained thioindigo, which has not been reported previously as a product of DBT biodegradation. In mineral salts medium, HFBT was sufficiently stable to allow biodegradation studies with a mixed microbial culture over a 3- to 4-week period. High-performance liquid chromatography analyses showed that HFBT was removed from the medium. 2-Mercaptophenylglyoxalate, detected as benzothiophene-2,3-dione, was found in an HFBT-degrading mixed culture, and the former appears to be a metabolite of HFBT. This mixed culture also mineralized HFBT to CO2.


1969 ◽  
Vol 15 (10) ◽  
pp. 1231-1236 ◽  
Author(s):  
J. E. Zajic ◽  
B. Volesky ◽  
Angela Wellman

A fungus which grows well on a mineral salts solution with natural gas as the carbon source is described and provisionally identified as a Graphium species. Its taxonomic relation to several genera is presented. This organism was isolated from sewage after selection by enrichment techniques and continuous culture. The fermentor was operated at ambient temperatures, 28 °C ± 2, at a volume of 10 liters with a dilution rate of 10 liters/4 days to 10 liters/1.7 days. Coty's mineral salts medium gave the highest tissue yield. When the pH of the incoming mineral salts medium was decreased stepwise from 7.0 to 5.0 the pH of the reactor became self-adjusting, varying from around 2.7 to 3.5, and the dry weight of microbial tissue obtained varied from 65 to 275 mg/h. Also present in the continuous culture was an acid tolerant bacterium, which, when isolated, grew well on natural gas, methanol, and ethanol, and a strain of Trichoderma, which, when isolated, did not use natural gas as a carbon source. In mixed culture the Trichoderma is thought to grow on metabolites produced by either or both the Graphium and the acid-tolerant bacterium during oxidation of natural gas. The nature of the relationship is being investigated. The mixed culture has been under continuous cultivation for 18 months.


2020 ◽  
Vol 299 ◽  
pp. 1064-1068 ◽  
Author(s):  
Aleksandr Bulaev ◽  
Vitaliy Melamud ◽  
Anna Boduen

Tank bioleaching of substandard arsenic-bearing sulfide copper–zinc concentrate, containing 1.70, 6.22, and 7.30% of arsenic, copper, and zinc, was performed. The concentrate contained pyrite, chalcopyrite, tennantite, and sphalerite. Bioleaching was performed at 40°C using a mixed culture of acidophilic microorganisms in two modes. In the first mode, pulp density was 10%, while in the second it comprised 15%. Bioleaching made it possible to extract 17 and 70% of copper and zinc in the first mode, and 15 and 72% of copper and zinc in the second mode. The results obtained that bioleaching can be an effective approach to remove zinc from substandard copper-zinc concentrates. At the same time, copper minerals, including arsenic-bearing mineral tennantite, may be comparatively resistant to bioleaching, so requires the development of novel hydrometallurgical approaches for effective processing.


Author(s):  
M. Grigoryev ◽  
N. Chernogradskaya

Animals imported to Yakutia from other regions fall into feeding and housing conditions that differ from their usual agro-climatic conditions, which causes the problem of their adaptation. Yakutia is one of the areas where the feed of its own production has a lack of basic minerals, which affects the health and productivity of animals, which has an additional negative influence on the adaptation process of imported cattle. In order to replenish macro- and microelements in the body, it is necessary to introduce various local mineral feed additives, premixes, and use mineral salts into the ration. Under the conditions of Central Yakutia the influence of local mineral feed additives (zeolite of the Khonguruu Deposit in the Suntar district and sapropels of local lakes) containing macro- and microelements that increase the meat productivity of steers has been studied. As a result of the research the influence of local mineral feed additives on meat productivity and physiological condition of Hereford steers has been established. Influence of zeolite and sapropel in a complex with mineral salts on digestibility of nutrients of the ration and use of nitrogen, calcium and phosphorus by experimental animals has been defined. The influence of feed additives on the quality of meat products has been studied. The results have shown that the use of local mineral feed additives in the composition of ration of steers during the fattening period at a dose of 0,7 g zeolite per 1 kg of live weight of the animal and 200 g of sapropel in combination with 10 g of mineral salts contributed to the gain in live weight, carcass weight, carcass yield, yield of edible parts, and economic efficiency of fattening. For the entire period of the experiment the gain in live weight in groups was: in control group 2222,9 kg, in the 1st experimental group 2396,2 kg, in the 2nd experimental group 2471,1 kg. The total economic effect for the 1st experimental group for the period of experiment amounted to 44,3 thousand Rubles, for the 2nd experimental group 78,0 thousand Rubles or per 1 head/day 14,06 and 24,76 Rubles, respectively.


Rumen ciliates still have mysterious secrets and influences in ruminants. This study investigated the effect of transfaunation of pure and mixed cultures of rumen ciliates on physical clinical examination, selected serum parameters and milk profile in defaunated lactating dairy goats. A number of 8 Baladi native breed goats were randomly classified into two groups each one containing 4 goats. Pure culture group was transfaunated with 6 ml of pure culture of Holotricha spp., while mixed culture group was transfaunated with 6 ml of mixed culture of 81.85% Holotricha and 18.15% Ophryoscolex spp. once weekly for three consecutive weeks, after defaunation of both groups using 30 ml of 8% SLS for two consecutive days. Serum and milk samples were collected weekly for three successive weeks to study effect of type of ciliate culture, duration of transfaunation and their interaction. Results revealed that transfaunation of pure and mixed cultures of rumen ciliates had no effect on physical examination with minimal non-significant improvement of calcium, inorganic phosphorous, total protein and globulin in serum of defaunated goats. Transfaunation of pure or mixed cultures of rumen ciliates within three weeks could not improve significantly decreased milk fat % of defaunated goats without any effect on other measured milk profile parameters. It is concluded that further investigations on transfaunation without prior defaunation should be performed using different pure and mixed cultures of rumen ciliates for therapeutic and productive purposes.


1995 ◽  
Vol 31 (9) ◽  
pp. 101-107 ◽  
Author(s):  
Chongchin Polprasert ◽  
Charles N. Haas

Anaerobic reactors were operated in a semi-batch mode and fed with the dual substrates glucose (G) plus acetic acid (Ac) as primary organic sources to study the effect of sulfate on COD oxidation. With glucose, COD removal by methane formation was seriously inhibited, resulting in COD accumulation in the reactor. Although acetic acid can be consumed by some sulfate-reducing species, it was not a major substrate for sulfate reduction, but was largely responsible for methane formation in the anaerobic mixed culture used in this study. With dual substrates, extreme inhibition of methanogenesis did not occur as did with glucose alone. Instead, methanogens were found to work in harmony with acid formers as well as sulfate reducers to oxidise COD. Interestingly, from 12-hour monitoring, increased G/Ac COD ratios decreased COD removal rates as well as biogas production, but resulted in higher sulfate reduction. This suggests that there should be an optimal feed G/Ac COD ratio, for which removal of both organics could be maximised.


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