Anaerobic-light Conditions Research Articles

C/N conversion and pigment production of Blastochloris sulfoviridis characterized by bacteriochlorophyll b under near-infrared single-wavelength laser

High carbon use efficiency (CUE) of photosynthetic bacteria (PSB) can concurrently increase biomass and reduce CO2 emissions. In the PSB study, light-oxygen conditions are crucial factors influencing the growth of these bacteria. Bacteriochlorophyll (BChl) b (absorption spectra: 970–1040 nm), due to its unique absorption spectrum, can be considered a crucial complement to BChl a (absorption spectra: 780–890 nm). We investigate the effects of four light-oxygen conditions on biomass, C/N conversion, and pigment production using five individual light sources in Blastochloris sulfoviridis (B. sulfoviridis), producing BChl b, isolated using 940±10 nm laser unexpectedly. Biomass, CUE, and pigment production follow the order under different light-oxygen conditions: light-anaerobic > light-aerobic > dark-aerobic > dark-anaerobic. The maximum biomass (1386.88 mg/L), highest CUE (0.95 g-biomass/g-CODremoved and 0.49 g-biomass carbon/g-CODremoved), and highest pigment production are observed under full spectrum (40 W)-anaerobic, 940-anaerobic, and 850-anaerobic conditions, respectively. Compared to light-aerobic, the nitrogen-fixing ability of B. sulfoviridis is enhanced under light-anaerobic conditions. This study contributes to research on resource recovery and greenhouse gas emissions reduction in PSB wastewater treatment.

Outdoor biohydrogen production by thermotolerant Rhodopseudomonas pentothenatexigens KKU-SN1/1 in a cluster of ten bioreactors system.

In tropical regions, the viability of outdoor photo-fermentative biohydrogen production faces challenges arising from elevated temperatures and varying light intensity. This research aimed to explore how high temperatures and outdoor environments impact both biohydrogen production and the growth of purple non-sulfur bacteria. Our findings revealed the potential of Rhodopseudomonas spp. as a robust outdoor hydrogen-producing bacteria, demonstrating its capacity to thrive and generate biohydrogen even at 40°C and under fluctuating outdoor conditions. Rhodopseudomonas harwoodiae NM3/1-2 produced the highest cumulative biohydrogen of 223mL/L under anaerobic light conditions at 40°C, while Rhodopseudomonas harwoodiae 2M had the highest dry cell weight of 2.93g/L. However, R. harwoodiae NM3/1-2 demonstrated the highest dry cell weight of 3.99g/L and Rhodopseudomonas pentothenatexigens KKU-SN1/1 exhibited the highest cumulative biohydrogen production of 400mL/L when grown outdoors. In addition, the outdoor enhancement of biohydrogen production was achieved through the utilization of a cluster of ten bioreactors system. The outcomes demonstrated a notable improvement in biohydrogen production efficiency, marked by the highest daily biohydrogen production of 493mL/Ld by R. pentothenatexigens KKU-SN1/1. Significantly, the highest biohydrogen production rate was noted to be 17 times greater than that observed in conventional batch production methods. This study is the first to utilize R. pentothenatexigens and R. harwoodiae for sustained biohydrogen production at high temperatures and in outdoor conditions over an extended operational period. The successful utilization of a clustered system of ten bioreactors demonstrates potential to scale-up for industrial biohydrogen production.

Multidimensional optimization for accelerating light-powered biocatalysis in Rhodopseudomonas palustris

BackgroundWhole-cell biocatalysis has been exploited to convert a variety of substrates into high-value bulk or chiral fine chemicals. However, the traditional whole-cell biocatalysis typically utilizes the heterotrophic microbes as the biocatalyst, which requires carbohydrates to power the cofactor (ATP, NAD (P)H) regeneration.ResultsIn this study, we sought to harness purple non-sulfur photosynthetic bacterium (PNSB) as the biocatalyst to achieve light-driven cofactor regeneration for cascade biocatalysis. We substantially improved the performance of Rhodopseudomonas palustris-based biocatalysis using a highly active and conditional expression system, blocking the side-reactions, controlling the feeding strategy, and attenuating the light shading effect. Under light-anaerobic conditions, we found that 50 mM ferulic acid could be completely converted to vanillyl alcohol using the recombinant strain with 100% efficiency, and > 99.9% conversion of 50 mM p-coumaric acid to p-hydroxybenzyl alcohol was similarly achieved. Moreover, we examined the isoprenol utilization pathway for pinene synthesis and 92% conversion of 30 mM isoprenol to pinene was obtained.ConclusionsTaken together, these results suggested that R. palustris could be a promising host for light-powered biotransformation, which offers an efficient approach for synthesizing value-added chemicals in a green and sustainable manner.Graphical

Performance of fish sludge solubilization and phototrophic bioconversion by purple phototrophic bacteria for nutrient recovery in aquaponic system

Nutrient recovery from fish sludge in aquaponics is crucial to improve the economic output of a system sustainably and hygienically. Currently, fish sludge is treated using conventional anaerobic and aerobic mineralization, which does not allow the recovery of valuable nutrients in fish wastes. In this study, a two-stage approach (named as solubilization process and phototrophic bioconversion) is proposed to convert fish sludge into mineral nutrients and biomass nutrients using purple phototrophic bacteria (PPB), thereby promoting the growth of plants and fish simultaneously in aquaponics. Anaerobic and aerobic solubilization methods are tested to pretreat the fish sludge, generating substrates for PPB. Anaerobic solubilization yields 2.1 times more soluble chemical oxygen demand (SCOD) and 3.7 times more total volatile fatty acid (t-VFA) from fish sludge compared with aerobic solubilization. The anaerobic solubilization effluent indicates a CODt-VFA/SCOD of 60% and a VFA comprising 13.3% acetate and 49.0% propionate for PPB. The phototrophic bioconversion using anaerobic solubilization effluent under the light-anaerobic condition results in the highest biomass yield (0.94 g CODbiomass/g CODremoved) and the highest PPB dominance (Ectothiorhodospira, 58.7%). The anaerobic solubilization and light-anaerobic phototrophic bioconversion achieves 54.1% of carbon recovery efficiency (CRE) (in terms of COD), as well as 44.8% and 91.3% of nutrient recovery efficiency (NRE) for N and P. A novel multiloop aquaponic system combined with PPB-based nutrient recovery is proposed for the reuse of mineral nutrients and PPB biomass generated from fish sludge.

Potential of Phototrophic Purple Nonsulfur Bacteria to Fix Nitrogen in Rice Fields.

Biological nitrogen fixation catalyzed by Mo-nitrogenase of symbiotic diazotrophs has attracted interest because its potential to supply plant-available nitrogen offers an alternative way of using chemical fertilizers for sustainable agriculture. Phototrophic purple nonsulfur bacteria (PNSB) diazotrophically grow under light anaerobic conditions and can be isolated from photic and microaerobic zones of rice fields. Therefore, PNSB as asymbiotic diazotrophs contribute to nitrogen fixation in rice fields. An attempt to measure nitrogen in the oxidized surface layer of paddy soil estimates that approximately 6–8 kg N/ha/year might be accumulated by phototrophic microorganisms. Species of PNSB possess one of or both alternative nitrogenases, V-nitrogenase and Fe-nitrogenase, which are found in asymbiotic diazotrophs, in addition to Mo-nitrogenase. The regulatory networks control nitrogenase activity in response to ammonium, molecular oxygen, and light irradiation. Laboratory and field studies have revealed effectiveness of PNSB inoculation to rice cultures on increases of nitrogen gain, plant growth, and/or grain yield. In this review, properties of the nitrogenase isozymes and regulation of nitrogenase activities in PNSB are described, and research challenges and potential of PNSB inoculation to rice cultures are discussed from a viewpoint of their applications as nitrogen biofertilizer.

Citrulline Accumulation Mechanism of Pediococcus acidilactici and Weissella confusa in Soy Sauce and the Effects of Phenolic Compound on Citrulline Accumulation.

Citrulline is one of the major precursors of ethyl carbamate in soy sauce, and the accumulation of citrulline is attributed to the metabolism of arginine by bacteria with the arginine deiminase (ADI) pathway. However, key strains and factors affecting citrulline accumulation are not yet clear. In this study, two key strains of Pediococcus acidilactici and Weissella confusa were isolated from soy sauce moromi, and the regularity of citrulline formation was studied. Results showed that the conversion rates from arginine to citrulline (A/C rate) and the citrulline accumulation ability of W. confusa and P. acidilactici significantly increased in the presence of different concentrations of NaCl, indicating that salt stress was the main factor for citrulline accumulation. The inconsistent expression of arc genes by salt stress was the reason for citrulline accumulation for P. acidilactici, but for W. confusa, it may be due to the influence of arginine/citrulline on the transportation system: the intracellular citrulline could neither transport to extracellular space nor convert into ornithine. Environmental factors greatly influenced citrulline accumulation of the two key bacteria; A/C rate and citrulline formation in both strains decreased at low temperature (15°C) under high salt stress, but opposite effects were observed for the two key strains under anaerobic light condition. Moreover, quercetin and gallic acid significantly decreased the A/C rate and citrulline accumulation ability of the two key strains. The optimal quercetin and gallic acid as suggested by simulation experiment were 100 and 10 mg/l, respectively, and the lowest A/C rate of 28.4% and citrulline level of 1326.7 mg/l were achieved in the simulation system. This study explored the main factors for citrulline formation by the two key strains and proposed a targeted way to control citrulline in soy sauce.

Enhancement of photosynthetic bacteria biomass production and wastewater treatment efficiency by zero-valent iron nanoparticles

Photosynthetic bacteria (PSB) wastewater treatment is a novel technology for wastewater purification and resources recovery but is restricted by low efficiency. This paper applied zero-valent iron nanoparticles (Fe0 NPs) to enhance its performance. Results showed that 20mg/L Fe0 NPs under light-anaerobic condition significantly increased the PSB biomass production and wastewater chemical oxygen demand removal by 122% and 164.3%, and shortened the time required for wastewater purification by 33%; these effects were far more better than the addition of Fe2+. The mechanism was because the addition of Fe0 NPs promoted the intracellular ATP content and pigments (carotenoid and bacteriochlorophyll) contents, and up-regulated dehydrogenase and succinate dehydrogenase activity; the increase rate reached 38.7%, 39.6%, 22.0%, 23.9% and 218.2%, respectively.

Experimental Optimization of Green Hydrogen Production from Phototrophic Bacteria Rhodobacter sphaeroides

Background and Objective: This study utilizes Rhodobacter sphaeroides bacteria for the photoproduction of hydrogen under various cultural conditions. R. sphaeroides was isolated from sewage water. We have examined different carbon and nitrogen sources for hydrogen production and further established the conditions for optimum hydrogen production by R. sphaeroides. Methods: The cumulative hydrogen produced by the bacteria at various intervals of time was measured using a Gas Chromatograph. Initially, by classical one factor at a time method, it was found that Benzoate and Glycine promote higher amounts of hydrogen production under anaerobic light conditions after 96 h. Results: The production was also observed to be enhanced in the presence of growth factors B12. Further, the Response Surface Methodology (RSM) was employed to optimize the hydrogen production. The first level of optimization was done using Box-Behnken Design (BBD) followed by Central Composite Design (CCD) method. The maximum production of hydrogen achieved by BBD and CCD was 6.8 ml/30 ml and 8.12 ml/30 ml, respectively. The significant model predicted is a quadratic model with R2 value 0.9459. Conclusion: Moreover, work presented here suggests an environment-friendly approach of harvesting H2, which could meet energy demand as clean fuel via the green route.

Optimization for enhanced hydrogen production from Rhodobacter sphaeroides using response surface methodology

In the present study, Rhodobacter sphaeroides isolated from sewage water was investigated for photoproduction of hydrogen under different cultural conditions. The variation was done in carbon and nitrogen sources along with growth factors. It was found that lactose promoted more amounts of hydrogen production under anaerobic light conditions followed by mannitol, galactose, and sucrose respectively. Uracil was observed as a better nitrogen source as compared to histidine and thiourea. After screening most appropriate carbon source, nitrogen source and growth factor by the classical approach, statistical optimization technique opted for the enhancement of hydrogen production. The response surface methodology adopted in the present work is an efficient tool for strategic experimental design for optimizing process parameters of a multivariable process. Firstly, experiments were performed according to Box-Behnken design. The model predicted is quadratic with a high value of R2 i.e. 0.9681 and maximum production recorded was 6.8 ml/30 ml. Thereafter, Central composite design based experiments were performed and 7.6 ml/30 ml production was achieved with an R2 value of 0.8848 fitted inthe quadratic model. The work presented here suggests a green approach of enhanced hydrogen production to meet the future demand of clean fuel.

Sulfide-dependent Photoautotrophy in the Filamentous Anoxygenic Phototrophic Bacterium, Chloroflexus aggregans.

Chloroflexus aggregans is a thermophilic filamentous anoxygenic phototrophic bacterium frequently found in microbial mats in natural hot springs. C. aggregans often thrives with cyanobacteria that engage in photosynthesis to provide it with an organic substrate; however, it sometimes appears as the dominant phototroph in microbial mats without cyanobacteria. This suggests that C. aggregans has the ability to grow photoautotrophically. However, photoautotrophic growth has not been observed in any cultured strains of C. aggregans. We herein attempted to isolate a photoautotrophic strain from C. aggregansdominated microbial mats in Nakabusa hot spring in Japan. Using an inorganic medium, we succeeded in isolating a new strain that we designated “ACA-12”. A phylogenetic analysis based on 16S rRNA gene and 16S-23S rRNA gene internal transcribed spacer (ITS) region sequences revealed that strain ACA-12 was closely related to known C. aggregans strains. Strain ACA-12 showed sulfide consumption along with autotrophic growth under anaerobic light conditions. The deposited elemental sulfur particles observed by microscopy indicated that sulfide oxidation occurred, similar to that in photoautotrophic strains in the related species, C. aurantiacus. Moreover, we found that other strains of C. aggregans, including the type strain, also exhibited a slight photoautotrophic growing ability, whereas strain ACA-12 showed the fastest growth rate. This is the first demonstration of photoautotrophic growth with sulfide in C. aggregans. The present results strongly indicate that C. aggregans is associated with inorganic carbon incorporation using sulfide as an electron donor in hot spring microbial mats.

Enhanced hydrogen production performance of cbbR &pycA inactived R.sphaeroides mutant by improving the ammonium tolerance

Three mutants were constructed in this study employing R. sphaeroides HY01 as wildtype strain: a cbbR gene partially deleted mutant assigned HR02 (cbbR-), a transposon mutant based on HR02 with insertional inactivation on pycA gene named HRT16 (cbbR-,ΔpycA) and a double-deletion mutant HDR02 (cbbR-, pycA-). The effects of double-gene disruption in R. sphaeroides HY01 on the growth and H2 generation were studied. The growth of R. sphaeroides HR02 under light anaerobic condition with NH4Cl as nitrogen source was repressed obviously. The H2 yields of transposon insertion mutant HRT16 with better growth characteristic were enhanced by 2.0%, 10.5%, and 26.8% comparing with HY01 under different NH4+-N concentration conditions (0.6, 1.2 and 1.8 mM NH4Cl supplemented, respectively), while the corresponding maximum H2 production rates were improved by 15.9%, 6.2% and 46.1%. With 1.2 mM NH4Cl, the H2 production of HDR02 was increased by 3.6% comparing with its parental strain HY01, and its maximum H2 production rate approached to that of HRT16. Double-gene mutants revealed enhanced H2 production performance by improving the ammonium tolerance, contrarying to the single mutant strain. These results implied the superposition effect of genes and the validity of transposon mutagenesis for screening mutants with enhanced H2 production.

Impact of cultural conditions on photoproduction of hydrogen by Allochromatium sp. GSKRLMBKU-01 isolated from marine water of Visakhapatnam

In the present study, photoproduction of hydrogen by Allochromatium sp. strain GSKRLMBKU-01 isolated from marine water was measured under different cultural conditions. Hydrogen production was measured by using a Gas chromatography using argon gas as a carrier. Among different carbon and nitrogen sources used, succinate induced maximum hydrogen (5.68 ± 0.27 mL) production by immobilized cells, while free cells recorded 4.24 ± 0.30 mL of hydrogen under anaerobic light conditions. Immobilization of cells resulted in increased production of hydrogen. Ammonium chloride promoted more amounts of hydrogen production (2.68 ± 0.29 mL) by free cells, whereas glycine enhanced the hydrogen production upto 4.82 ± 0.36 mL in immobilized cells. In formic acid and urea, less hydrogen production was observed in both free and immobilized cells compared to other sources. Cumulative hydrogen production by the bacterium was recorded with the progress in incubation period. Incubation period of 192 h, pH of 7.0 and temperature at 30 °C were found to be optimum for the maximum hydrogen production. Significance of the above results was discussed in light of existing literature.

Benchmark study of photosynthetic bacteria bio-conversion of wastewater: Carbon source range, fundamental kinetics of substrate degradation and cell proliferation

Photosynthetic bacteria (PSB)-bioconversion is a novel method for wastewater treatment and resource recovery. But fundamental knowledge on effective substrate range, cell proliferation and substrate degradation kinetics are lacking. This paper studied the efficient range of carbon source (in terms of COD) and the fundamental kinetics of COD degradation and cell proliferation of this technology. Results showed that the efficient concentration range of carbon source was 500–40,000mg·L−1 COD for PSB, which covers most organic wastewaters. Then the substrate degradation and cell proliferation kinetics were studied using Michaelis-Menten equation and Monod equation. The Vmax, Km, μmax and Ks was 4.80d−1, 7382mg·L−1, 1.23d−1 and 7714mg·L−1 under light-anaerobic condition, and they were 4.27d−1, 4813mg·L−1, 0.59d−1 and 21,295mg·L−1 under dark-aerobic condition; which fell in the range of conventional biological wastewater technologies. This benchmark study lays foundation for further study and scale-up of this novel technology.

Nitrite-reducing ability is related to growth inhibition by nitrite in Rhodobacter sphaeroides f. sp. denitrificans.

Growth inhibition of Rhodobacter sphaeroides f. sp. denitrificans IL106 by nitrite under anaerobic-light conditions became less pronounced when the gene encoding nitrite reductase was deleted. Growth of another deletion mutant of the genes encoding nitric oxide reductase was severely suppressed by nitrite. Our results suggest that nitrite reductase increases the sensitivity to nitrite through the production of nitric oxide.

Utilization of Vegetable Waste Juice by Purple Non-Sulfur Bacterium (<i>Afifella marina</i> Strain ME) for Biomass Production

This experiment was conducted to determine the possibility of utilization of vegetable waste juice in the production of purple non-sulfur bacterium Afifella marina biomass. Bacterium was cultured in four diluted such as, 10%, 20%, 30% and 40% (v/v) vegetable waste juices. In addition synthetic 112 media were used as control to compare the growth characteristics of Afifella marine. The bacterium Afifella marina grew well in 10% diluted vegetable waste juice in anaerobic light condition with the highest production of 5.02 g/l dry cell weight in fifth day of culture, whereas the highest total carotenoid production of 0.87 mg/g dry cell weight was recorded in third day of culture. The highest dry cell weight productions recorded in 10% of VWJ was significantly higher compared to four other treatments (F = 14.63; p = 0.00). However, the total carotenoid production of bacteria in 10% VWJ showed no significant difference compared to the carotenoid production in 112 synthetic media, but was significantly higher compared to three other treatments (P = 0.00). The bacterium, Afifella marina has the ability to use vegetable waste juice at certain level for the production of bacterial biomass.

Chromate Reduction by Purple Non Sulphur Phototrophic Bacterium Rhodobacter sp. GSKRLMBKU–03 Isolated from Pond Water

A purple non sulphur phototrophic bacterium (PNSB) Rhodobacter sp. GSKRLMBKU–03 was isolated from pond water of Thadoba forest, Chandrapoor District, India and its ability to reduce hexavalent chromium was discussed in the present study. Both free and immobilized cells of this bacterium were employed for chromate reduction. Immobilization of cells resulted in enhanced reduction of chromate. Sodium alginate entrapment could reduce chromate up to 40 μM, while free cells of Rhodobacter sp. GSKRLMBKU–03 could reduce about 35 µM of chromate on 8th day of its incubation under anaerobic light conditions. Both free and immobilized cells could reduce chromate even on the 20th day. Optimal growth and chromate reduction was observed on 8th day of its incubation period. The final pH of the free cells and immobilized cells in growth medium was recorded in the range of 7.5 ± 0.25–7.6 ± 0.15 at optimal incubation period respectively. The optimal growth of free cells and immobilized cells in terms of dry cell weight (DCW) was recorded as 1.80 ± 0.15 and 2.2 ± 0.20 g/L respectively. The optimal growth observed upon complete chromate reduction. The results are expressed in mean and standard deviations which are statistically significant at P ≤ 0.05 level. The employment of Rhodobacter sp. in bioremediation to detoxify chromium in large-scale systems is proposed.

Enhancing protein to extremely high content in photosynthetic bacteria during biogas slurry treatment

This work proposed a novel approach to achieve an extremely high protein content in photosynthetic bacteria (PSB) using biogas slurry as a culturing medium. The results showed the protein content of PSB could be enhanced strongly to 90% in the biogas slurry, which was much higher than reported microbial protein contents. The slurry was partially purified at the same time. Dark-aerobic was more beneficial than light-anaerobic condition for protein accumulation. High salinity and high ammonia of the biogas slurry were the main causes for protein enhancement. In addition, the biogas slurry provided a good buffer system for PSB to grow. The biosynthesis mechanism of protein in PSB was explored according to theoretical analysis. During biogas slurry treatment, the activities of glutamate synthase and glutamine synthetase were increased by 26.55%, 46.95% respectively.

Potential of Rhodobacter capsulatus Grown in Anaerobic-Light or Aerobic-Dark Conditions as Bioremediation Agent for Biological Wastewater Treatments

The use of microorganisms to clean up wastewater provides a cheaper alternative to the conventional treatment plant. The efficiency of this method can be improved by the choice of microorganism with the potential of removing contaminants. One such group is photosynthetic bacteria. Rhodobacter capsulatus is a purple non-sulfur bacterium (PNSB) found to be capable of different metabolic activities depending on the environmental conditions. Cell growth in different media and conditions was tested, obtaining a concentration of about 108 CFU/mL under aerobic-dark and 109 CFU/mL under anaerobic-light conditions. The biomass was then used as a bioremediation agent for denitrification and nitrification of municipal wastewater to evaluate the potential to be employed as an additive in biological wastewater treatment. Inoculating a sample of mixed liquor withdrawn from the municipal wastewater treatment plant with R. capsulatus grown in aerobic-dark and anaerobic-light conditions caused a significant decrease of N-NO3 (>95%), N-NH3 (70%) and SCOD (soluble chemical oxygen demand) (>69%), independent of the growth conditions. A preliminary evaluation of costs indicated that R. capsulatus grown in aerobic-dark conditions could be more convenient for industrial application.

Construction and phenotypic characterization of M68, an RruI quorum sensing knockout mutant of the photosynthetic alphaproteobacterium Rhodospirillum rubrum

Many bacterial species communicate using a complex system known as quorum sensing (QS) in which gene expression is controlled in response to cell density. In this study an N-acylhomoserine lactone (AHL) synthase (Rru_A3396) knockout mutant (M68) of Rhodospirillum rubrum S1H (WT) was constructed and characterized phenotypically under light anaerobic conditions. Results showed that R. rubrum WT produces unsubstituted, 3-OH and 3-oxo-substituted AHLs with acyl chains ranging from 4 to 14 carbons, with 3-OH-C8 being the most abundant. Growth, pigment content and swimming motility were found to be under the control of this LuxI-type QS system. In addition, cultivation in a low shear environment put forward the aggregative phenotype of M68 and linked biofilm formation to QS in R. rubrum S1H. Interestingly, QS-mutant M68 continued to produce decreased levels of 3-OH-C8-HSL, probably due to the presence of an extra HdtS-type AHL synthase.

Isolation and Characterization of a Purple Non-Sulfur Photosynthetic Bacterium Rhodopseudomonas faecalis Strain A from Swine Sewage Wastewater.

A purple non-sulfur photosynthetic bacterium (PNSB), PSB Strain A was isolated from swine sewage wastewater. Phylogenetic analysis revealed that PSB Strain A was most closely related to Rhodopseudomonas faecalis. Growth of the isolate under anaerobic-light conditions with a variety of carbon sources was investigated. Both PSB Strain A and the standard strain showed good growth with acetic acid, propionic acid, and n-butyric acid at a concentration of 20 mM. At the high concentration of 200 mM, PSB Strain A showed better growth in pyruvate, acetate, propionate, succinate and malate. By applying PSB Strain A to treat swine sewage wastewater, the concentration of VFAs, which were acetic acid and propionic acid, decreased from 158.0 mM to 120.2±2.9 mM, and 14.9 mM to 9.3±0.9 mM, respectively, after 216-h incubation. After 330-h incubation, the concentrations of TOC and ammonia nitrogen dropped from 4508.0 mg/L to 3104.0±451.5 mg/L, and 629.7 mg/L to 424.1±7.4 mg/L, respectively. The isolated PSB Strain A showed almost the same efficiency compared with the standard strain on the removal of VFAs and TOC. The results suggest the possibility of using the isolated strain to treat swine sewage wastewater.