Symbiosis and competition among sulfate reduction, filamentous sulfur, denitrification, and poly-p accumulation bacteria in the anaerobic-oxic activated sludge of a municipal plant

1996 ◽  
Vol 34 (5-6) ◽  
pp. 119-128 ◽  
Author(s):  
Ryoko Yamamoto-Ikemoto ◽  
Saburo Matsui ◽  
Tomoaki Komori ◽  
E. J. Bosque-Hamilton

Symbiosis and competition were examined among sulfate reducing bacteria (SRB), filamentous sulfur bacteria (FSB), denitrification bacteria (DNB) and poly-P accumulation bacteria (PAB) in the activated sludge of a municipal plant operated under anaerobic-oxic conditions. Batch experiments were carried out using settled sewage from the same plant as the substrate under several conditions. Under oxic conditions, both sulfate reduction and sulfide oxidation occurred simultaneously, making a symbiotic relationship of SRB and FSB for establishment of a sulfur cycle sustaining the energy requirements. Under anoxic conditions, denitrification was dominant because DNB outcompeted PAB and SRB for organic acids. Under anaerobic conditions, phosphate release and sulfate reduction occurred simultaneously. SRB produced for moles of acetate from four moles of propionate and/or unknown substances by reduction of three moles of sulfate. PAB competed with sulfate-reducing bacteria for organic acids such as propionate. However, PAB utilized acetate produced by SRB.

1998 ◽  
Vol 37 (4-5) ◽  
pp. 599-603 ◽  
Author(s):  
Ryoko Yamamoto-Ikemoto ◽  
Saburo Matsui ◽  
Tomoaki Komori ◽  
Edja. Kofi. Bosque-Hamilton

The interactions between filamentous sulfur bacteria (FSB), sulfate reducing bacteria (SRB) and poly-P accumulating bacteria (PAB) in the activated sludge of a municipal plant operated under anaerobic-oxic conditions were examined in batch experiments using return sludge (RAS) and settled sewage. Phosphate release and sulfate reduction occurred simultaneously under anaerobic conditions. SRB were more sensitive to temperature changes than PAB. SRB played an important role in the decomposition of propionate to acetate. When the sulfate reduction rates were high, there was a tendency for the maximum release of phosphate also to be high. This was explained by the fact that PAB utilized the acetate produced by SRB. Sulfur oxidizing bacteria were sensitive to temperature change. When the sulfate reduction rate was high, the sulfide oxidizing rate was also high and filamentous bulking occurred. The results showed that sulfate reduction was a cause of filamentous bulking due to Type 021N that could utilize reduced sulfur.


Pyrite ◽  
2015 ◽  
Author(s):  
David Rickard

The two basic processes concerning pyrite in the environment are the formation of pyrite, which usually involves reduction of sulfate to sulfide, and the destruction of pyrite, which usually involves oxidation of sulfide to sulfate. On an ideal planet these two processes might be exactly balanced. But pyrite is buried in sediments sometimes for hundreds of millions of years, and the sulfur in this buried pyrite is removed from the system, so the balance is disturbed. The lack of balance between sulfide oxidation and sulfate reduction powers a global dynamic cycle for sulfur. This would be complex enough if this were the whole story. However, as we have seen, both the reduction and oxidation arms of the global cycle are essentially biological—specifically microbiological—processes. This means that there is an intrinsic link between the sulfur cycle and life on Earth. In this chapter, we examine the central role that pyrite plays, and has played, in determining the surface environment of the planet. In doing so we reveal how pyrite, the humble iron sulfide mineral, is a key component of maintaining and developing life on Earth. In Chapter 4 we concluded that Mother Nature must be particularly fond of pyrite framboids: a thousand billion of these microscopic raspberry-like spheres are formed in sediments every second. If we translate this into sulfur production, some 60 million tons of sulfur is buried as pyrite in sediments each year. But this is only a fraction of the total amount of sulfide produced every year by sulfate-reducing bacteria. In 1982 the Danish geomicrobiologist Bo Barker Jørgensen discovered that as much as 90% of the sulfide produced by sulfate-reducing bacteria was rapidly reoxidized by sulfur-oxidizing microorganisms. Sulfate-reducing microorganisms actually produce about 300 million tons of sulfur each year, but about 240 million tons is reoxidized. The magnitude of the sulfide production by sulfate-reducing bacte­ria can be appreciated by comparison with the sulfur produced by volcanoes. As discussed in Chapter 5, it was previously supposed that all sulfur, and thus pyrite, had a volcanic origin. In fact volcanoes produce just 10 million tons of sulfur each year.


1994 ◽  
Vol 30 (11) ◽  
pp. 201-210 ◽  
Author(s):  
Ryoko Yamamoto-Ikemoto ◽  
Saburo Matsui ◽  
Tomoaki Komori

Effects of anoxic-oxic conditions on the growth of sulfate reduction, poly-P accumulation and filamentous sulfur bacteria were examined in the laboratory scale sequential batch reactors. In the anoxic-oxic conditions, denitrification bacteria are dominant. The growth of sulfate reducing bacteria and poly-P accumulating bacteria was suppressed. The number of sulfate reducing bacteria in the activated sludge was below 104 MPN/g MLSS, and the sulfate reduction rate was very low. Filamentous bulking was also suppressed. On the other hand, when nitrate was removed from the artificial wastewater, sulfate reducing bacteria could grow predominantly in the anaerobic conditions. The number of sulfate reducing bacteria was about 106∼107 MPN/g MLSS and the sulfate reduction rate increased (0.17 ∼ 0.21 g SO4/g MLSS·hr). Filamentous bacteria Type 021N increased over 103 cm/mg MLSS. Sodium molybdate was added to the artificial wastewater in order to prevent sulfate reduction. When the concentration of sodium molybdate increased to 980 mg/L, the number of sulfate reducing bacteria decreased to 103 ∼ 104 MPN/g MLSS and the sulfate reduction rate decreased. Filamentous bulking was completely suppressed in these conditions. These results show that sulfate reduction is a main trigger of the filamentous bulking due to Type 021N that can utilize reduced sulfur for an energy source.


1998 ◽  
Vol 37 (4-5) ◽  
pp. 605-608 ◽  
Author(s):  
Dirk de Beer ◽  
Andreas Schramm ◽  
Cecilia M. Santegoeds ◽  
Helle K. Nielsen

We found anoxic zones in aerated activated sludge flocs, and demonstrated denitrification under normal operating conditions. Sulfate reduction was not found. Micro-environments and microbial conversions in flocs from bulking and non-bulking activated sludge were determined with microsensors for H2S, O2, NO2− and NO3−. Denitrification and sulfate reduction rates were mmeasured with 15N- and 35S-tracer techniques. We showed that under normal reactor conditions (ca. 20% air saturation) anoxic zones develop within flocs allowing denitrification. The denitrification rates amounted to 40% of the rates under anoxic conditions. At 100% air saturation no anoxic zones were found and no denitrification occurred. However, in flocs from bulking sludge (at 20% air saturation) anoxic zones were absent and denitrification did not occur. In bulking sludge only at total anoxia was denitrification found. Confocal microscopy showed that flocs from bulking sludge were much looser than those from non-bulking sludge. The absence of anoxic zones and of denitrification was attributed to the open floc structure, allowing advective oxygen transport. Sulfate reduction was not detected in any of the sludges tested by microsensors or by tracer techniques even under anoxic conditions. this indicates that the sulfur cycle (sulfate reduction and sulfide oxidation) does not play a role in mineralization processes and bulking in activated sludge. Preliminary molecular work (in situ hybridization with the 16S-rRNA probe SRB385) indicated the presence of small amounts of sulfate reducing bacteria in all sludges. Either the probe is not specific or the sulfate reducers present are not active under reactor conditions.


1991 ◽  
Vol 23 (4-6) ◽  
pp. 927-935 ◽  
Author(s):  
Ryoko Ikemoto Yamamoto ◽  
Tomoaki Komori ◽  
Saburo Matsui

Sulfate reduction in the activated sludge cultivated with glucose and peptone in the sequential batch reactor system and the continuous anaerobic-oxic system was examined. In both systems, sulfate reduction occurred. When the sulfate reduction ratio increased, Type 021N or Beggiatoa sp. grew in the sludge and settling characteristics became poor. These results suggested that sulfate reduction was a cause of growth of the filamentous bacteria which could utilize sulfide for the energy source. There was a tendency that the greater the sulfate reduction ratio was, the smaller the phosphate removal ratio was. As a result of batch experiments using the mixed liquor and the wall growing sludge, it was demonstrated that the sulfate reducing bacteria grown in the activated sludge mainly produced acetate from propionate and lactate. About 107~108 MPN of sulfate reducing bacteria grew in 1 g of the activated sludge and about 109 MPN grew in 1 g of the wall growing sludge.


1999 ◽  
Vol 39 (7) ◽  
pp. 41-47 ◽  
Author(s):  
Satoshi Okabe ◽  
Hisashi Satoh ◽  
Tsukasa Itoh ◽  
Yoshimasa Watanabe

The vertical distribution of sulfate-reducing bacteria (SRB) in microaerophilic wastewater biofilms grown on fully submerged rotating disk reactors (RDR) was determined by the conventional culture-dependent MPN method and in situ hybridization of fluorescently-labelled 16S rRNA-targeted oligonucleotide probes for SRB in parallel. Chemical concentration profiles within the biofilm were also measured using microelectrodes for O2, S2-, NO3- and pH. In situ hybridization revealed that the SRB probe-stained cells were distributed throughout the biofilm even in the oxic surface zone in all states from single scattered cells to clustered cells. The higher fluorescence intensity and abundance of SRB probe-stained cells were found in the middle part of the biofilm. This result corresponded well with O2 and H2S concentration profiles measured by microelectrodes, showing sulfate reduction was restricted to a narrow anaerobic zone located about 500 μm below the biofilm surface. Results of the MPN and potential sulfate reducing activity (culture-dependent approaches) indicated a similar distribution of cultivable SRB in the biofilm. The majority of the general SRB probe-stained cells were hybridized with SRB 660 probe, suggesting that one important member of the SRB in the wastewater biofilm could be the genus Desulfobulbus. An addition of nitrate forced the sulfate reduction zone deeper in the biofilm and reduced the specific sulfate reduction rate as well. The sulfate reduction zone was consequently separated from O2 and NO3- respiration zones. Anaerobic H2S oxidation with NO3- was also induced by addition of nitrate to the medium.


2021 ◽  
Author(s):  
Rui Liu ◽  
Yeqi Shan ◽  
Shichuan Xi ◽  
Xin Zhang ◽  
Chaomin Sun

Zero-valent sulfur (ZVS) is a critical intermediate in the biogeochemical sulfur cycle. Up to date, sulfur oxidizing bacteria have been demonstrated to dominate the formation of ZVS. In contrast, formation of ZVS mediated by sulfate reducing bacteria (SRB) has been rarely reported. Here, we report for the first time that a typical sulfate reducing bacterium Desulfovibrio marinus CS1 directs the formation of ZVS via sulfide oxidation. In combination with proteomic analysis and protein activity assays, thiosulfate reductase (PhsA) and sulfide: quinone oxidoreductase (SQR) were demonstrated to play key roles in driving ZVS formation. In this process, PhsA catalyzed thiosulfate to form sulfide, which was then oxidized by SQR to form ZVS. Consistently, the expressions of PhsA and SQR were significantly up-regulated in strain CS1 when cultured in the deep-sea cold seep, strongly indicating strain CS1 might form ZVS in its real inhabiting niches. Notably, homologs of phsA and sqr widely distributed in the metagenomes of deep-sea SRB. Given the high abundance of SRB in cold seeps, it is reasonable to propose that SRB might greatly contribute to the formation of ZVS in the deep-sea environments. Our findings add a new aspect to the current understanding of the source of ZVS.


2017 ◽  
Vol 12 (1) ◽  
pp. 82-91 ◽  
Author(s):  
Ivan Kushkevych ◽  
Monika Vítězová ◽  
Tomáš Vítěz ◽  
Milan Bartoš

AbstractThe production of high-quality methane depends on many factors, including temperature, pH, substrate, composition and relationship of the microorganisms. The qualitative and quantitative composition of methanogenic and sulfate-reducing microorganisms and their relationship in the experimental bioreactors has never been studied. The aim of this research was to characterize, for the first time, the diversity of the methanogenic microorganisms and sulfate-reducing bacteria, and study their relationship and biogas production in experimental bioreactors. Amplification of 16S rRNA gene fragments was carried out. Purified amplicons were paired-end sequenced on an Illumina Mi-Seq platform. The dominant morphotypes of these microorganisms in the bioreactor were homologous (99%) by the sequences of 16S rRNA gene to theMethanosarcina,Thermogymnomonas,Methanoculleusgenera andArchaeondeposited in GenBank. Three dominant genera of sulfate-reducing bacteria,Desulfomicrobium,DesulfobulbusandDesulfovibrio, were detected in the bioreactor. The phylogenetic trees showing their genetic relationship were constructed. The diversity and number of the genera, production of methane, hydrogen sulfide and hydrogen in the bioreactor was investigated. This research is important for understanding the relationship between methanogenic microbial populations and other bacterial physiological groups, their substrate competition and, in turn, can be helpful for controlling methanogenesis in bioreactors.


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