Evaluation of efficacy of indigenous acidophile- bacterial consortia for removal of pollutants from coffee cherry pulping wastewater

Indigenous bacteria as potential agents for trace metal remediation in industrial wastewater

Water pollution is a burning issue that can originate from both urbanization and industrialization. This study aimed to evaluate the industrial wastewater collected from Hayatabad Industrial Estate and to use indigenous bacteria, Pseudomonas aeruginosa and Enterobacter aerogenes for bioremediation. The water samples collected were analyzed for physicochemical parameters and microbial pollution. To analyze the pollution removal efficiency by indigenous bacterial species, a pot experiment was performed for 14 days. Before and after experiment, the water samples were analyzed for trace metal concentration by Atomic Absorption Spectroscopy. The biochemical and molecular analysis confirmed the presence of two bacterial species (P. aeruginosa and E. aerogenes). The industrial wastewater treated with these isolated bacterial species showed significantly decreased level of electrical conductivity (42.33-86.45%), dissolved oxygen (16.35-63.37%), biological oxygen demand (33.33-80.62%), chemical oxygen demand (00-83.52%), total suspended solids (00-80%), and total dissolved solids (0.00-54.93%). The P. aeruginosa removal efficiency for Cu, Cd, and Pb was ranging 77.58-82.35%, 19.67-50%, and 20.40-91.66%, respectively. Similarly, the E. aerogenes removed Cu, Cd, and Pb in the range of 47.05-60.61%, 54.55-62.29%, and 85.21-91.6%, respectively. Phytotoxicity results revealed that the wastewater treated with both P. aeruginosa and E. aerogenes gives better Triticum sp. % germination rate, leaf length, and root and shoot weight. The highest plant % germination was showed by treated P. aeruginosa in control (100%), followed by E. aerogenes in control (100%). The t- test analysis showed the concentration of trace metals (TM) in industrial wastewater was significantly reduced (p ≤ 0.05) by bacterio-remediation. The study concluded that both bacterial species are active in the removal of pollution and TM from the wastewater.

Microbial consortium with multifunctional attributes for the plant growth of eggplant (Solanum melongena L.)

In the past few decades, the pressure of higher food production to satisfy the demand of ever rising population has inevitably increased the use synthetic agrochemicals which have deterioration effects. Biostimulants containing beneficial microbes (single inoculants and microbial consortium) were found as an ideal substitute of synthetic chemical fertilizers. In recent years, microbial consortium is known as a better bioinoculant in comparison to single inoculant bioformulation because of multifarious plant growth-promoting advantages. Looking at the advantageous effect of consortium, in present investigation, different bacteria were isolated from rhizospheric soil and plant samples collected from the Himalayan mountains on the green slopes of the Shivaliks, Himachal Pradesh. The isolated bacteria were screened for nitrogen (N) fixation, phosphorus (P) solubilization and potassium (K) solubilization plant growth promoting attributes, and efficient strains were identified through 16S rRNA gene sequencing and BLASTn analysis. The bacteria showing a positive effect in NPK uptake were developed as bacterial consortium for the growth promotion of eggplant crop. A total of 188 rhizospheric and endophytic bacteria were sorted out, among which 13 were exhibiting nitrogenase activity, whereas 43 and 31 were exhibiting P and K solubilization traits, respectively. The selected three efficient and potential bacterial strains were identified using 16S rRNA gene sequencing as Enterobacter ludwigii EU-BEN-22 (N-fixer; 35.68 ± 00.9 nmol C2H4 per mg protein per h), Micrococcus indicus EU-BRP-6 (P-solubilizer; 201 ± 0.004 mg/L), and Pseudomonas gessardii EU-BRK-55 (K-solubilizer; 51.3 ± 1.7 mg/mL), and they were used to develop a bacterial consortium. The bacterial consortium evaluation on eggplant resulted in the improvement of growth (root/shoot length and biomass) and physiological parameters (chlorophyll, carotenoids, total soluble sugar, and phenolic content) of the plants with respect to single culture inoculation, chemical fertilizer, and untreated control. A bacterial consortium having potential to promote plant growth could be used as bioinoculant for horticulture crops growing in hilly regions.

The Role of Flavobacterium enshiense R6S-5-6 in the Wetland Ecosystem Revealed by Whole-Genome Analysis

The wetland is an important ecosystem for purifying pollutants and circulating nutrients. Numerous microorganisms contribute to maintaining this function. We obtained Flavobacterium enshiense R6S-5-6 which was isolated from Ungok (Ramsar) Wetland and conducted whole-genome sequencing to investigate what contribution R6S-5-6 could make to the wetland community. The complete genome sequence of R6S-5-6 has a size of 3,251,289 bp with 37.68% of GC content. Gene annotation revealed that R6S-5-6 has several pathways to break down pollutants, including denitrification, assimilatory sulfate reduction (ASR), and polyphosphate-accumulating process. Furthermore, R6S-5-6 has genes that can have a positive effect on plants living in wetlands, such as storing essential nutrients, promoting plant growth, and protecting plants against pathogens.

Pollutant removal from cheese processing effluent using effective indigenous natural scavengers

The goal of this study was to come up with an efficient method for treating cheese production wastewater. Because the effluent has a higher concentration of organic and inorganic materials, the indigenous microbial treatment process was used to effectively remove total dissolved solids (TDS), chemical oxygen demand (COD), and color without the addition of any nutrients. The indigenous microorganisms were tested for color, TDS, and COD elimination by growing them in "nutrient broth medium" loaded with different amounts of cheese effluent. The isolates were identified by 16S rRNA sequencing, and the results revealed that strain 1 was Enterobacter cloacae, strain 2 was Lactococcus garvieae, and strains 3 and 4 were Bacillus cereus and Bacillus mycoides, respectively. After 36 h of incubation, the data were evaluated. Among all the microbes, E. cloacae reduced TDS and COD from the effluent the most (80 ± 0.2% and 87 ± 0.4% COD, respectively). When compared to individual species, consortia were more efficient (86 ± 0.2% TDS and 90 ± 0.3% COD). On treatment, the correlation coefficient "r" for TDS and COD elimination was found to be 1, resulting in a positive linear connection. The current study suggests that microbial therapies are both effective and environmentally beneficial.

What compound inside biocoagulants/bioflocculants is contributing the most to the coagulation and flocculation processes?

Biocoagulants and bioflocculants are alternative items that can be used to substitute the utilization of common-chemical coagulants and flocculants. Biocoagulants/bioflocculants can be extracted from animals, microorganisms, and plants. Moreover, biocoagulants/bioflocculants have specific characteristics that contribute to the coagulation and flocculation processes. The active compounds inside biocoagulants/bioflocculants vary and correspond to the specific working mechanisms, including charge neutralization, sweep coagulation, adsorption, bridging, and patch flocculation. This review paper summarizes the characteristics of biocoagulants/bioflocculants from different sources and its performance in treating various pollutants. Furthermore, this paper discusses the most contributing compounds and functional groups of biocoagulants/bioflocculants that can be related to their working mechanisms. Several functional groups and compounds in biocoagulants/bioflocculants are highlighted in this review article, as well as the correlation between the highlighted groups/compounds to the aforementioned coagulation-flocculation mechanisms. In addition, current knowledge gaps in the study of biocoagulants/bioflocculants and future approaches that may serve as research directions are also emphasized. This review article is expected to shed information on the characteristics of biocoagulants/bioflocculants, which may then become a focus in the optimization to obtain higher performance in future application of coagulation-flocculation processes.

Competence of Lepironia articulata in eradicating chemical oxygen demand and ammoniacal nitrogen in coffee processing mill effluent and its potential as green straw

Phytoremediation is an environmentally friendly technique in wastewater treatment because of its sustainability, cost-effectiveness, and simplicity. This study was conducted to examine the feasibility of use of Lepironia articulata, a potential phytoremediation plant that is native to Malaysia, in remediating coffee processing mill effluent (CPME). The aim was to determine effluent concentration or contaminant load that the plant can resist, while simultaneously results in the good removal of pollutants during phytoremediation. Four brushes of L. articulata were planted individually in a pail/reactor (mentioned as reactor afterward) containing 3 kg of sand and exposed to five different concentrations of CPME (0%, 30%, 50%, 75%, and 100%). The initial chemical oxygen demand (COD) values were 510, 3100, 4200, 7290, and 8470 mg/L, respectively, and ammoniacal nitrogen (AN) concentrations were 26, 128, 225, 376, and 509 mg/L, respectively. The height, appearance, and efficiency in removing COD and AN of each plant was observed throughout the 35-day exposure period. Results showed that plants exposed to 75% CPME demonstrated better growth than those exposed to other concentrations and exhibited the highest COD and AN removal rates (85.0% and 84.0%, respectively), providing evidence that L. articulata can be used as a phytoremediation agent of CPME with an initial COD concentration of 7290 mg/L and AN concentration of 376 mg/L. This study highlights its support to the Sustainable Development Goals adopted by the United Nations, particularly the reclamation of plant biomass used as a treatment agent and conversion into biodegradable straws. Moreover, this study adds an attractive additional point of transforming waste into resource with the proposed wastewater treatment technology.