Isolation and Characterization of a Molybdenum-reducing and Carbamate-degrading Serratia sp. strain Amr-4 in soils from Egypt

Physical or chemical procedures could efficiently remove contaminants including pesticides such as carbamates from high concentrations of toxicants. Bioremediation, on the other hand, is frequently a less expensive option in the long term when used at low concentrations. Isolation of multiple toxicants removing microorganisms is the goal of bioremediation. In this paper we report on the molybdenum reduction of the bacterium and its ability to grow on the carbamates carbofuran and carbaryl as carbon sources. Both the carbamates carbofuran and carbaryl cannot support molybdenum reduction when used as the sole carbon sources. Between pH 6.0 and 6.8 and between 30 and 34 oC, the bacterium is most efficient in converting molybdate to Mo-blue. For molybdate reduction, glucose was shown to be the strongest electron donor, with maltose and sucrose coming in second and third, respectively, and d-mannitol and d-adonitol coming in last. Phosphate concentrations of 2.5 to 7.5 mM and molybdate concentrations of 20 to 30 mM are also needed. Identical to that of a decreased phosphomolybdate, the Mo-blue produced by the new Mo-reducing bacteria has an absorption spectrum similar to prior Mo-reducing bacteria. Inhibition of molybdenum reduction was 73.3, 50.1, 50.1 and 20.7 percent, respectively, by mercury, copper, silver and lead at 2 ppm. The bacterium was tentatively identified as Serratia sp. strain Amr-4 after biochemical investigation. This bacterium's ability to detoxify a variety of toxicants is highly sought after, making it a significant bioremediation agent.

The effectivity of Biduri combined with indigenous bacteria in mercury absorption

Heavy metals pollution, especially Mercury (Hg), is one of the most serious environmental problems. The presence of excessive Hg will cause soil degradation and threaten the life of the ecosystem, for that remediation is necessary. Biduri is known to be able to absorb heavy metals, but there is no research on the ability of Biduri in absorb Hg. The use of indigenous bacteria is expected to increase the absorption of Mercury by Biduri. The purpose of this study was to determine the potential of Biduri combined with indigenous bacteria and Agrobacterium sp I37 in absorbing of Hg in the soil. The experimental was designed as factorial with completely randomized design, consisting of 2 factors namely Bioremediation agent (A0: without bioremediation agent, A1: indigenous bacteria, A3: Agrobacterium sp I37) and Hg dosage (D0: without Hg, D1: Hg 0.3 µg.g-1, D2: Hg 0.51 µg.g-1). The results showed that the combination of Biduri with indigenous bacteria + 0.3 µg.g-1 Hg shows highest absorption of Hg at 57.19 µg (99.24% higher than control) and reduce soil Hg levels by 0.09 µg.g-1. Biduri is a hyperaccumulator plant because it is able to absorb more than 10 µg.g-1 of mercury.

Efecto del pH y Sales Inorgánicas en la Degradación de Colorantes Industriales por Pleurotus Djamor

En la presente investigación se planteó el uso de la cepa Pd318 del hongo Pleurotus djamor como agente biorremediador, con el objetivo de evaluar su capacidad para degradar el colorante reactivo azul 19 (A19). Para ello se estudió la influencia que tienen cinco sales inorgánicas en el crecimiento y actividad lignolítica del hongo. Un cribado de sales inorgánicas en placa determinó que las sales CaCl2.2H2O y MnSO4.5H2O tienen mayor influencia en el desarrollo micelial y actividad lignolítica de la cepa. Ensayos de fermentación líquida (FEL) con diferentes combinaciones a distintas concentraciones de las sales de calcio y manganeso permitieron demostrar la capacidad de degradación del colorante azul 19 a los 7 días de fermentación líquida a temperatura ambiente y agitación constante. Los máximos porcentajes de degradación del colorante fueron obtenidos con las combinaciones A1B1 y A2B1 con 43,47% y 41,36%, respectivamente. Se observó que a un pH de 5 unidades se favorece la degradación del colorante. Los estudios en placa señalaron que la adición de sales de calcio y manganeso en 10 días de incubación favorecieron el desarrollo micelial y la actividad lignolítica de Pd318, mientras que en un sistema FEL de 7 días, únicamente la adición de manganeso influye favorablemente a la actividad lignolítica del hongo y en consecuencia a su capacidad de degradación de azul 19. Palabra clave: Colorante azul 19, degradación de colorantes, enzimas lignolíticas, Pleurotus djamor. Abstract In the present investigation, the use of the Pd318 strain of the Pleurotus djamor fungus as a bioremediation agent was proposed, with the aim of evaluating its ability to degrade reactive dye blue 19 (A19). For this, the influence of five inorganic salts on the growth and lignolytic activity of the fungus was studied. A plate screening of inorganic salts determined that the CaCl2.2H2O and MnSO4.5H2O salts have a greater influence on the mycelial development and lignolytic activity of the strain. Liquid fermentation tests (FEL) with different combinations at different concentrations of the calcium and manganese salts allowed to demonstrate the degradation capacity of the blue dye 19, after 7 days of liquid fermentation at room temperature and constant stirring, the maximum degradation percentages of the dye were obtained with the combinations A1B1 and A2B1 with 43.47% and 41.36% respectively. It was observed that at a pH of 5 units the degradation of the dye is favored. The plate studies indicated that the addition of calcium and manganese salts in 10 days of incubation, favored mycelial development and the lignolytic activity of Pd318, while in a 7 day FEL system, only the addition of manganese favorably influenced the lignolytic activity of the fungus and consequently its ability to break down blue 19. Keywords: Blue dye 19, dye degradation, lignolytic enzymes, Pleurotus djamor.

Potential of Variovorax paradoxus isolate BFB1_13 for bioremediation of BTEX contaminated sites

Here, we report and discuss the applicability of Variovorax paradoxus strain BFB1_13 in the bioremediation of BTEX contaminated sites. Strain BFB1_13 was capable of degrading all the six BTEX-compounds under both aerobic (O2 conc. 8 mg l−1) and micro-aerobic/oxygen-limited (O2 conc. 0.5 mg l−1) conditions using either individual (8 mg‧l−1) or a mixture of compounds (~ 1.3 mg‧l−1 of each BTEX compound). The BTEX biodegradation capability of SBP-encapsulated cultures (SBP—Small Bioreactor Platform) was also assessed. The fastest degradation rate was observed in the case of aerobic benzene biodegradation (8 mg l−1 per 90 h). Complete biodegradation of other BTEX occurred after at least 168 h of incubation, irrespective of the oxygenation and encapsulation. No statistically significant difference was observed between aerobic and microaerobic BTEX biodegradation. Genes involved in BTEX biodegradation were annotated and degradation pathways were predicted based on whole-genome shotgun sequencing and metabolic analysis. We conclude that V. paradoxus strain BFB1_13 could be used for the development of reactive biobarriers for the containment and in situ decontamination of BTEX contaminated groundwater plumes. Our results suggest that V. paradoxus strain BFB1_13—alone or in co-culture with other BTEX degrading bacterial isolates—can be a new and efficient commercial bioremediation agent for BTEX contaminated sites.

Draft De Novo Genome Assembly of Acinetobacter pittii Strain VKPM B-3780, a Prospective Multifunctional Bioremediation Agent

Acinetobacter pittii strain B-3780 is a prospective degrader of oil and methanol, isolated from industrial wastewater. Here, we present the draft genome sequence of strain B-3780, obtained using Illumina sequencing of the fragment genomic library.

Indigenous multiresistant bacteria of Cupriavidus pauculus IrC4 isolated from Indonesia as a heavy metal bioremediation agent

Irawati W, Winoto SE, Kusumawati L, Pinontoan R. 2021. Indigenous multiresistant bacteria of Cupriavidus pauculus IrC4 isolated from Indonesia as a heavy metal bioremediation agent. Biodiversitas 22: 3349-3355. Heavy metal pollution is a serious environmental problem because it endangers humans, animals, and plants. Bioremediation of heavy metals using bacteria is an effective method to remove heavy metals. Cupriavidus pauculus IrC4 is an indigenous multi-resistant bacteria isolated from Indonesia. This study aims to determine the growth of this strain in a medium containing cadmium, mercury, lead, copper, and its ability to accumulate heavy metal. Bacterial resistance was observed by cultivating bacteria on a Luria Bertani medium containing various concentrations of heavy metals. Heavy metal accumulation was measured using atomic absorption spectrophotometer. The study showed that this strain could grow in a solid medium containing 5 mM cadmium, 13 mM lead, and 4 mM mercury, also in 0.5 mM of the heavy metal mixture. A high concentration of heavy metals resulted in lag phase elongation and logarithmic growth phase inhibition. C. pauculus IrC4 could accumulate copper, lead, and cadmium and lead up to 371.42 mg, 254.4 mg, 5.8 mg heavy metals per gram of dry weight of cells, respectively. In conclusion, this strain is a promising bacterium for use as a heavy metal bioremediation agent.

Complete Genome Sequence of Tsuneonella flava SS-21NJ, a Potential Oil Sludge Bioremediation Agent

ABSTRACT We report here the complete genome sequence of Tsuneonella flava strain SS-21NJ, which was isolated from oil sludge from Shengli Oilfield in Dongying, Shandong Province, China. These results provide basic information for functional genomics and oil degradation research of Tsuneonella strains.

THE REDUCTION OF Cr(VI) IN SOIL BY Microbacterium sp. STRAIN SpR3 IN VERMICOMPOST CARRIER

Reduksi Cr(VI) pada Tanah Menggunakan Microbacterium sp. Strain SpR3 dengan Bahan Pembawa Vermikompos Kromium hexavalen [Cr(VI)] adalah polutan yang berasal dari kegiatan industri. Microbacterium sp. strain SpR3 dapat digunakan sebagai agen bioremediasi Cr(VI). Kemampuan agen biologi untuk mereduksi Cr(VI) umumnya meningkat bila diinokulasi dalam media pembawa. Tujuan penelitian ini adalah untuk menganalisis kemampuan Microbacterium sp. strain SpR3 dalam mengurangi Cr(VI) serta membandingkannya dengan kondisi ketika diinokulasi dalam media pembawa vermikompos. Pengamatan dilakukan selama tujuh hari pada tiga perlakuan yang berbeda, yakni Microbacterium sp. strain SpR3 dengan dan tanpa media pembawa vermikompos yang diinokulasi pada tanah steril yang mengandung 50 ppm Cr(VI), dan tanah steril tanpa inokulasi bakteri yang mengandung 50 ppm Cr(VI). Variabel yang diamati adalah jumlah bakteri, konsentrasi, dan kecepatan reduksi Cr(VI) oleh bakteri tersebut di dalam tanah pada T0 (hari ke-0) dan T7 (hari ke-7). Hasil penelitian ini menyimpulkan bahwa vermikompos bisa digunakan sebagai media pembawa Microbacterium sp. strain SpR3 karena dapat meningkatkan jumlah bakteri sampai 2 × 1010 CFU g-1 di dalam tanah dan dapat mengurangi Cr(VI) dengan kecepatan 0,095 mg L-1 jam-1. Hexavalent chromium [Cr(VI)] is a pollutant originated from industrial activities. Microbacterium sp. strain SpR3 can be used as Cr(VI) bioremediation agent. The ability of bioagent to reduce Cr(VI) usually improves when inoculated in a carrier. This research aimed to assess the ability of Microbacterium sp. strain SpR3 to reduce Cr(VI) in soil and compare its ability when inoculated in vermicompost carrier. Observations were carried out for seven days on three different treatments, namely Microbacterium sp. strain SpR3 with and without vermicompost inoculated in sterile soils containing 50 ppm Cr(VI), and sterile soils containing 50 ppm Cr(VI) without bacterial inoculation. The observed variables were the number of bacteria, the concentration of Cr(VI) and the rate of Cr(VI) reduction by these bacteria in the soil at T0 (day 0) and T7 (day 7). It was concluded that vermicompost could be used as a carrier of Microbacterium sp. strain SpR3 as it could increase the number of the bacteria to 2 × 1010 CFU g-1 in soil and could reduce Cr(VI) at the rate of 0.095 mg L-1 h-1.