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A M Ferro Orozco, E M Contreras, N E Zaritzky
The objective of the present work was to analyze the interrelationship between the aerobic degradation of BPA and readily biodegradable substrates by activated sludge (AS) in semi-continuous reactors (SCRs). AS were obtained from three SCRs fed with glucose, acetate or peptone. AS from these reactors were used as inocula for three SCRs that were fed with each biogenic substrate, and for three SCRs that were fed with the biogenic substrate and BPA. In all cases, dissolved organic carbon (DOC), BPA, total suspended solids (TSS) and respirometric measurements were performed...
September 21, 2018: Biodegradation
Malin Hultberg, Hristina Bodin
Recent research has demonstrated the potential of using filamentous fungi to form pellets with microalgae (biopellets), in order to facilitate harvesting of microalgae from water following algae-based treatment of wastewater. In parallel, there is a need to develop techniques for removing organic pollutants such as pesticides and pharmaceuticals from wastewater. In experiments using the microalga Chlorella vulgaris, the filamentous fungus Aspergillus niger and biopellets composed of these microorganisms, this study investigated whether fungal-assisted algal harvesting can also remove pesticides from contaminated water...
September 1, 2018: Biodegradation
Zhenguo Chen, Xiaojun Wang, Xiaozhen Chen, Jing Chen, Xiaoyang Gu
Denitrifying granular sludge reactor holds better nitrogen removal efficiency than other kinds of denitrifying reactors, while this reactor commonly needs seeding anaerobic granular sludge and longer period for start-up in practice, which restricted the application of denitrifying granular sludge reactor. This study presented a rapid and stable start-up method for denitrifying granular sludge. An upflow sludge blanket (USB) reactor with packings was established with flocculent activated sludge for treatment of high concentration nitrite wastewater...
August 23, 2018: Biodegradation
Ningke Hou, Yongzhen Xia, Xia Wang, Huaiwei Liu, Honglei Liu, Luying Xun
Many industrial activities produce H2 S, which is toxic at high levels and odorous at even very low levels. Chemolithotrophic sulfur-oxidizing bacteria are often used in its remediation. Recently, we have reported that many heterotrophic bacteria can use sulfide:quinone oxidoreductase and persulfide dioxygenase to oxidize H2 S to thiosulfate and sulfite. These bacteria may also potentially be used in H2 S biotreatment. Here we report how various heterotrophic bacteria with these enzymes were cultured with organic compounds and the cells were able to rapidly oxidize H2 S to zero-valence sulfur and thiosulfate, causing no apparent acidification...
August 23, 2018: Biodegradation
Jie Tang, Bo Liu, Ting-Ting Chen, Kai Yao, Lin Zeng, Chao-Yi Zeng, Qing Zhang
A novel beta-cypermethrin (Beta-CP)-degrading strain isolated from activated sludge was identified as Brevibacillus parabrevis BCP-09 based on its morphological and physio-biochemical characteristics, and 16S rRNA gene analysis. Strain BCP-09 could effectively degrade Beta-CP at pH 5.0-9.0, 20-40 °C, and 10-500 mg L-1 Beta-CP. Under optimal conditions (pH 7.41, 38.9 °C, 30.9 mg L-1 Beta-CP), 75.87% Beta-CP was degraded within 3 days. Beta-CP degradation (half-life, 33.45 h) and strain BCP-09 growth were respectively described using first-order-kinetic and logistic-kinetic models...
August 16, 2018: Biodegradation
Noomen Hmidet, Nawel Jemil, Moncef Nasri
This study investigated the coproduction of alkaline amylase and lipopeptides by Bacillus methylotrophicus DCS1 strain, as well as their biochemical characterisation. The best production of both amylase and biosurfactant was obtained when potato starch (10 g/L) and glutamic acid (5 g/L) were used as carbon and nitrogen sources, respectively. The bacterial strain was incubated for 48 h at 25 °C and 150 rpm. This strain produced a unique amylase as showed by zymography technique. The optima pH and temperature were 60-65 °C and 8...
August 10, 2018: Biodegradation
Imen Ghazala, Amir Bouallegue, Anissa Haddar, Semia Ellouz-Chaabouni
Response surface methodology was applied to optimize the production of biosurfactants from Bacillus mojavensis I4 using Box-Behnken design with four variables. The optimal variable combination was 3% of glucose as carbon source, 0.6% of glutamic acid as nitrogen source, temperature of 35 °C and 10 g/l of NaCl which yielded to an optimal production of 4.12 g/l. Compositional analysis and FTIR spectrum revealed that the extracted biosurfactants was a lipopeptides. The biosurfactants achieved a critical micelle concentration value of 100 mg/l...
July 20, 2018: Biodegradation
Lauren M Czaplicki, Monika Dharia, Ellen M Cooper, P Lee Ferguson, Claudia K Gunsch
Although ecological flexibility has been well documented in fungi, it remains unclear how this flexibility can be exploited for pollutant degradation, especially in the Ascomycota phylum. In this work, we assess three mycostimulation amendments for their ability to induce degradation in Trichoderma harzanium, a model fungus previously isolated from a Superfund site contaminated with polycyclic aromatic hydrocarbons. The amendments used in the present study were selected based on the documented ecological roles of ascomycetes...
July 13, 2018: Biodegradation
Duc Danh Ha
Thauera sp. strain DKT isolated from sediment utilized 2,4-dichlorophenoxyacetic acid (2,4D) and its relative compounds as sole carbon and energy sources under anaerobic conditions and used nitrate as an electron acceptor. The determination of 2,4D utilization at different concentrations showed that the utilization curve fitted well with the Edward model with the maximum degradation rate as 0.017 ± 0.002 mM/day. The supplementation of cosubstrates (glucose, acetate, sucrose, humate and succinate) increased the degradation rates of all tested chemical substrates in both liquid and sediment slurry media...
October 2018: Biodegradation
Chang Ding, Lisa Alvarez-Cohen, Jianzhong He
The dechlorinating Dehalococcoides mccartyi species requires acetate as carbon source, but little is known on its growth under acetate limiting conditions. In this study, we observed growth and dechlorination of a D. mccartyi-containing mixed consortium in a fixed-carbon-free medium with trichloroethene in the aqueous phase and H2 /CO2 in the headspace. Around 4 mM formate was produced by day 40, while acetate was constantly below 0.05 mM. Microbial community analysis of the consortium revealed dominance by D...
October 2018: Biodegradation
Melanie C Bruckberger, Trevor P Bastow, Matthew J Morgan, Deirdre Gleeson, Natasha Banning, Greg Davis, Geoffrey J Puzon
Once released into the environment, petroleum is exposed to biological and physical weathering processes which can lead to the formation and accumulation of highly recalcitrant polar compounds. These polar compounds are often challenging to analyse and can be present as an "unresolved complex mixture" (UCM) in total petroleum hydrocarbon (TPH) analyses and can be mistaken for natural organic matter. Existing research on UCMs comprised of polar compounds is limited, with a majority of the compounds remaining unidentified and their long-term persistence unknown...
October 2018: Biodegradation
Lijuan Feng, Rong Jia, Zhen Zeng, Guangfeng Yang, Xiangyang Xu
To enhance the startup and efficient simultaneous nitrification and denitrification for sewage treatment, sequencing batch biofilm reactors (SBBRs) partially coupled with rice husk were established and operated under various intermittent micro-aeration cycles (IMCs) and COD/N ratios under oxygen-limiting intermittent aeration conditions. Experimental results showed that the increase of IMCs with non-aeration/micro-aeration mode of (8 h/4 h)1 to (2 h/1 h)4 in a 12 h-cycle accelerated the startup performance and improved NH4 + -N and COD removal...
October 2018: Biodegradation
E Emilia Rios-Del Toro, Edgardo I Valenzuela, Nguyen E López-Lozano, M Guadalupe Cortés-Martínez, Miguel A Sánchez-Rodríguez, Omar Calvario-Martínez, Salvador Sánchez-Carrillo, Francisco J Cervantes
Availability of fixed nitrogen is a pivotal driver on primary productivity in the oceans, thus the identification of key processes triggering nitrogen losses from these ecosystems is of major importance as they affect ecosystems function and consequently global biogeochemical cycles. Denitrification and anaerobic ammonium oxidation coupled to nitrite reduction (Anammox) are the only identified marine sinks for fixed nitrogen. The present study provides evidence indicating that anaerobic ammonium oxidation coupled to the reduction of sulfate, the most abundant electron acceptor present in the oceans, prevails in marine sediments...
October 2018: Biodegradation
Chao Yang, Yingxia Tang, Hua Xu, Ning Yan, Naiyu Li, Yongming Zhang, Bruce E Rittmann
Pyridine and its heterocyclic derivatives are widely encountered in industrial wastewaters, and they are relatively recalcitrant to biodegradation. Pyridine biodegradation is initiated by two mono-oxygenation reactions that compete for intracellular electron donor (2H). In our experiments, UV photolysis of pyridine generated succinate, whose oxidation augmented the intracellular electron donor and accelerated pyridine biodegradation and mineralization. The first mono-oxygenation reaction always was faster than the second one, because electrons provided by intracellular electron donors were preferentially utilized by the first mono-oxygenase; this was true even when the concentration of 2HP was greater than the concentration of pyridine...
October 2018: Biodegradation
Yiu Fai Tsang, Yong Sik Ok, Ajit K Sarmah, Bin Cao, Ming Hung Wong
No abstract text is available yet for this article.
August 2018: Biodegradation
Joanna Brzeszcz, Paweł Kaszycki
Environmental pollution with petroleum toxic products has afflicted various ecosystems, causing devastating damage to natural habitats with serious economic implications. Some crude oil components may serve as growth substrates for microorganisms. A number of bacterial strains reveal metabolic capacities to biotransform various organic compounds. Some of the hydrocarbon degraders are highly biochemically specialized, while the others display a versatile metabolism and can utilize both saturated aliphatic and aromatic hydrocarbons...
August 2018: Biodegradation
Sok Kim, Min Seo Jeon, Jee Young Kim, Sang Jun Sim, Jong-Soon Choi, Joseph Kwon, Yoon-E Choi
In recent times, the treatment of harmful algal blooms (HABs) became an important environmental issue to preserve and remediate water resources globally. In the present study, the adsorptive removal of harmful algal species Microcystis aeruginosa directly from an aqueous medium was attempted. Waste biomass (Escherichia coli) was immobilized using polysulfone and coated using the cationic polymer polyethylenimine (PEI) to generate PEI-coated polysulfone-biomass composite fiber (PEI-PSBF). The density of M. aeruginosa in an aqueous medium (BG11) was significantly decreased by treatment with PEI-PSBF...
August 2018: Biodegradation
Xing Ya-Juan, Ji Jun-Yuan, Zheng Ping, Wang Lan, Ghulam Abbas, Jiqiang Zhang, Wang Ru, He Zhan-Fei
The autotrophic process for nitrogen removal has attracted worldwide attention in the field of wastewater treatment, and the performance of this process is greatly influenced by the size of granular sludge particles present in the system. In this work, the granular sludge was divided into three groups, i.e. large size (> 1.2 mm), medium size (0.6-1.2 mm) and small size (< 0.6 mm). The medium granular sludge was observed to dominate at high volumetric nitrogen loading rates, while offering strong support for good performance...
August 2018: Biodegradation
Jayanta Kumar Biswas, Anurupa Banerjee, Mahendra Kumar Rai, Jörg Rinklebe, Sabry M Shaheen, Santosh Kumar Sarkar, Madhab Chandra Dash, Anilava Kaviraj, Uwe Langer, Hocheol Song, Meththika Vithanage, Monojit Mondal, Nabeel Khan Niazi
The aim was to isolate, characterize, and explore potentials of gut bacteria from the earthworm (Metaphire posthuma) and imply these bacteria for remediation of Cu(II) and Zn(II). An extracellular polymeric substance (EPS) producing gut bacteria (Bacillus licheniformis strain KX657843) was isolated and identified based on 16S rRNA sequencing and phylogenetic analysis. The strain showed maximum tolerance of 8 and 6 mM for Cu(II) and Zn(II) respectively. It removed 34.5% of Cu(II) and 54.4% of Zn(II) at 25 mg L-1 after 72 and 96 h incubation respectively...
August 2018: Biodegradation
Shiping Zhang, Liang Wang, Wei Wei, Jiajun Hu, Shouhua Mei, Quanyu Zhao, Yiu Fai Tsang
Improved soil carbon sink capability is important for the mitigation of carbon dioxide emissions and the enhancement of soil productivity. Biochar and organic fertilizer (OF) showed a significant improving effect on microalgae in soil carbon sink capacity, and the ultimate soil total organic carbons with microalgae-OF, microalgae-biochar, microalgae-OF-biochar were about 16, 67 and 58% higher than that with microalgae alone, respectively, indicating that carbon fixation efficiency of microalgae applied in soil was improved with biochar and OF whilst the soil carbon capacity was promoted, the mechanism of which is illustrated through simulative experiments...
August 2018: Biodegradation
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