Sewage to energy: harnessing algae-fungi consortium for bioremediation

The treatment of oil-contaminated wastewater represents a significant environmental challenge. In this study, five highly efficient diesel-degrading bacterial strains were successfully isolated from oily wastewater, which was designated as Pseudomonas sp. ZC1, Vibrio sp. ZL2, Acinetobacter sp. ZY3, Citrobacter sp. GO5, and Enterobacter cloacae GM6. To construct an efficient bacterial consortium based on these five strains, the optimized strain combination of 26 different consortia composed of two, three, four, and five bacterial strains was conducted. The results suggested that a consortium comprising three strains (ZL2, ZY3, and GM6) showed the highest diesel degradation efficiency of 89.66% on day 3, while other strain combinations exhibited lower degradation rates and tended to require more time to achieve comparable efficiency. The orthogonal experiments further determined the optimal inoculation ratios of 1.0%, 0.5%, and 1.5% for strains ZL2, ZY3, and GM6 improved diesel degradation efficiency to 93.65% by day 3. The application of this consortium in the oily wastewater bioremediation confirmed its degrading capacity for n-alkanes (C8-C40) and polycyclic aromatic hydrocarbons (PAHs). This study highlights the excellent performance of the engineered bacterial consortium in the bioremediation of petroleum-contaminated wastewater, demonstrating its potential for scaling up to pilot and full-scale applications.

Since ancient times, we have worked with microbial consortia in a variety of contexts, including wastewater treatment, the production of biogas, additionally to biodegradation and bio cleansing. The great ability of microbial consortiums is, however, a very long way from being completely realized. Last few years have seen a surge in interest in biosynthesis and bioprocessing related to the understanding and use of microbial consortia. It can be difficult to implement complex tasks in a single population. Synthetic consortiums of microorganisms have long utilized in biotechnology procedures like waste management, agricultural farming, and fermentation. Today, microbial consortiums are being engineered for a range of uses by synthetic biologists. The division of collaborative work in consortia is crucial for the breakdown of environmental contaminants that are persistent, cultures need to be resilient to the complicated environment, which often needs several phases. As a result, bioremediation may greatly benefit from the use of synthetic microbial consortiums [1]. The created and improved synthetic microbial community can operate as a culture (seed culture) for ex situ remediation methods including biodegradation in smaller reactors and bio augmentation of in situ bioremediation practices. In order to prevent genetic contamination from environmental microorganisms, the use of designed microbial consortia is currently, to a large degree, restricted in carefully monitored bioprocesses. In this review, an overview of undefined naturally occurring microbial consortia and their application was discussed. We introduced the notion of synthetic microbial consortia, system biology, we discussed Importance of synthetic microbial consortia with relevant examples of how they add value to bio refineries. We did an overview of microbial consortia in biotechnological process, application of microbial consortia in bioremediation and biodegradation was further discussed.

<p><em>The bioremediation technique </em><em>for</em><em> a contaminated liquid waste of heavy metals using indigen</em><em>ous</em> bacteria is a convenient alternative to steps continues to be developed. The research aims to find out the effectiveness of an indigenous bacterial consortium<em></em><em> in bioremediation of contaminated liquid waste </em><em>by</em><em> cadmium </em><em>by</em><em> ex-situ. Experiments </em><em>were</em><em> arranged in RAL made in ex-situ where a liquid waste industry was given five treatments, namely control and four indigen</em><em>ous</em><em> bacterial consortia (A, D, E, and J) obtained from the isolation of bacteria originating from cadmium-contaminated of waste in Pasuruan </em><em>district</em><em>. Furthermore conducted observations of BOD<sub>5</sub>, COD, d.o. and Cd for seven days to find out the effectiveness of bioremediation. The results showed the four </em><em>indigenous </em><em>bacteria consortia have the bioremediation ability to reduce levels of </em><em>cadmium, </em><em>BOD<sub>5</sub>, COD, and increasing levels of DO. Indigen</em><em>ous</em><em> bacterial consortia D </em><em>has</em><em> the </em><em>best </em><em>ability of liquid industrial waste bioremediation </em><em>by</em><em> ex-situ. Indigen</em><em>ous</em><em> bacteria</em><em>l</em><em> consortia J </em><em>has</em><em> the </em><em>best of </em><em>capacity reduction levels of cadmium, </em><em>then the other of </em><em>indigen</em><em>ous</em><em> bacteria</em><em>l </em><em>consortia.</em><em></em></p><strong><em>Keywords:</em><em> indigenous bacterial, bioremediation, ex-situ, cadmium, liquid waste.</em></strong>

One of the primary issues brought about by the industrialization's rapid development is aquatic pollution. Utilizing microorganisms to remediate industrial wastewater (IWW) is a sustainable approach. This study was conducted to assess pollution load in Wupa wastewater treatment plant and to use introduced microbes (Bacillus subtillis and Aspergillus niger) individually and in a consortium for bioremediation. The Wupa wastewater treatment plant in Abuja provided the wastewater samples, which were then analysed for heavy metal content and other physicochemical characteristics. Measurements were made of the pH, colour, temperature, turbidity, electrical conductivity (EC), total suspended solids (TSS), chemical oxygen demand (COD), biological oxygen demand (BOD), and total dissolved solids (TDS). Wastewaters samples were subjected to heavy metal analysis using Atomic absorption spectrometry (AAS). For eight days, a container experiment was conducted to assess the effectiveness of the chosen species. Selected species were used to remediate the wastewater samples both alone and collectively. Following treatment, turbidity (41.2%), BOD (95.2%), COD (96%), TSS (87-99%), TDS (27-8%), and EC (45-8%) all showed significant decreases. Following the experiment, atomic absorption spectrophotometry was used to determine the metal concentrations in water samples. 98.4% of Zn, 92.4% of Fe, and 92.4% of Mn were eliminated by the chosen species. Heavy metal removal percentage from Wupa wastewater using Aspergillus niger and Bacillus subtillis. Zinc significantly (p>0.05) record high removal efficiency as compared to Mangane and Iron in the waste water treated with Bacillus subtilis, A. Niger and the combination of both organisms.The bioremoval efficiency of Aspergillus niger and Bacillus subtillis for heavy metals in Wupa wastewater. The control treatment significantly (p<0.05) has lower bioremoval efficiency of the heavy metals (Manganese, Iron and Zinc) when compared to the waste water treated with Bacillus subtilis, A. Niger and the combination of both organisms. Based on the findings of this study, it can be concluded that the Bacillus subtillis and Aspergillus niger and other ingineous wastewater isolsates had the capacity to resist and grow on heavy metals and thus contributes in the removal of heavy metals present in the wastewater by absorbing them which also increased the biomass of the microbes.

Synergistic degradation of pyrene by five culturable bacteria in a mangrove sediment-derived bacterial consortium

Enhanced decolorization and biodegradation of textile azo dye Scarlet R by using developed microbial consortium-GR

Aquatic pollution is one of the main problems due to rapid development in industrialization. The remediation of industrial wastewater (IWW) by microorganisms is an environmentally friendly technique. This study was conducted to assess pollution load in IWW and to use Bacillus pakistanensis and Lysinibacillus composti individually and in a consortium for bioremediation. The IWW was obtained from Hayatabad Industrial Estate and evaluated for physicochemical parameters and metal concentration. The pH, color, electrical conductivity (EC), turbidity, temperature, sulfide, fluoride, chloride, biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids (TDS), calcium hardness, magnesium hardness, and total hardness were noted as 6.82, 440 TCU, 1.195 mS/cm, 54.65 mg/L, 26.8 °C, 5.60 mg/L, 3.6 mg/L, 162 mg/L, 85.5 mg/L, 921 mg/L, 232 mg/L, 794 mg/L, 590 mg/L, 395 mg/L, and 985 mg/L, respectively. The metals such as manganese, copper, chromium, cadmium, cobalt, silver, nickel, calcium, magnesium, and lead were also analyzed as 1.23 mg/L, 0.81 mg/L, 2.12 mg/L, 0.18 mg/L, 0.151 mg/L, 0.24 mg/L, 1.12 mg/L, 0.113 mg/L, 14.5 mg/L, and 0.19 mg/L, respectively. A pot experiment was performed for two weeks to evaluate the efficiency of the selected species. The IWW and tap water (control) were treated with selected species, individually and in a consortium. After treatment, a considerable reduction was noted in the color 87.3%, EC 46.5%, turbidity 84.1%, sulfide 87.5%, fluoride 25.0%, chloride 91.3%, BOD 96.4%, COD 86.5%, TSS 90%, TDS 45.0%, Ca hardness 42.3%, Mg hardness 77.2%, and total hardness 52.2%. After the experiment, samples of water were also analyzed for metal concentrations by atomic absorption spectrophotometry. The selected species removed 99.3% of Mn, 99.6% of Cu, 97.8% of Cr, 94.4% of Cd, 46.3% of Co, 85.1% of Ag, 88.4% of Ni, 98.8% of Ca, 91.5% of Mg, and 90.5% of Pb. The t-test analysis showed that the treatment with the selected species significantly decreased the metal concentrations in the IWW (p ≤ 0.05).

Polycyclic Aromatic Hydrocarbons (PAHs) impose adverse effects on the environment and human life. The use of synthetic microbial consortia is promising in bioremediation of contaminated sites with these pollutants. However, the design of consortia taking advantage of natural interactions has been poorly explored. In this study, a dual synthetic bacterial consortium (DSC_AB) was constructed with two key members (Sphingobium sp. AM and Burkholderia sp. Bk), of a natural PAH degrading consortium. DSC_AB showed significantly enhanced degradation of PAHs and toxic intermediary metabolites relative to the axenic cultures, indicating the existence of synergistic relationships. Metaproteomic and gene-expression analyses were applied to obtain a view of bacterial performance during phenanthrene removal. Overexpression of the Bk genes, naph, biph, tol and sal and the AM gene, ahdB, in DSC_AB relative to axenic cultures, demonstrated that both strains are actively participating in degradation, which gave evidence of cross-feeding. Several proteins related to stress response were under-expressed in DSC_AB relative to axenic cultures, indicating that the division of labour reduces cellular stress, increasing the efficiency of degradation. This is the one of the first works revealing bacterial relationships during PAH removal in a synthetic consortium applying an omics approach. Our findings could be used to develop criteria for evaluating the potential effectiveness of synthetic bacterial consortia in bioremediation.

Metalloids are released into the environment due to the erosion of the rocks or anthropogenic activities, causing problems for human health in different world regions. Meanwhile, microorganisms with different mechanisms to tolerate and detoxify metalloid contaminants have an essential role in reducing risks. In this review, we first define metalloids and bioremediation methods and examine the ecology and biodiversity of microorganisms in areas contaminated with these metalloids. Then we studied the genes and proteins involved in the tolerance, transport, uptake, and reduction of these metalloids. Most of these studies focused on a single metalloid and co-contamination of multiple pollutants were poorly discussed in the literature. Furthermore, microbial communication within consortia was rarely explored. Finally, we summarized the microbial relationships between microorganisms in consortia and biofilms to remove one or more contaminants. Therefore, this review article contains valuable information about microbial consortia and their mechanisms in the bioremediation of metalloids.

Wood‑feeding termites as an obscure yet promising source of bacteria for biodegradation and detoxification of creosote-treated wood along with methane production enhancement

Bioremediation of oil spillage in soils using consortia of microbes beckons much exploration. The present study involves bioremediation of oil-contaminated soils from north Chennai, India, using indigenous microbial consortia. Totally, 32 positive oil degrading isolates were obtained from 3 different locations, i.e., petrol filling stations, automobile workshops and oil refineries. Substrate utilization patterns of individual isolates and the consortial sets were observed. Mixture of three common hydrocarbons (petrol, diesel and engine oil) was used for studies. The substrate oil utilized by consortia was taken for thin-layer and column chromatography which perfectly resulted in varied fractions of oil compared to the unused oil as control. The best consortia were used directly for bioremediation experiment. Three different oil-contaminated soils were used and bioremediation patterns were observed. The rate of bioremediation differed within soils, nevertheless all soils were almost 100 % reclaimed within 30 days. Bioremediation kinetics showed that the process corresponds to first-order kinetics and kinetic constants for the different soils ranged from 0.051 to 0.077/day. Assessment of detoxification of acute phytotoxicity owing to the pollutant oil was done, and results observed were significant. An increase of 25, 300 and 212 % in germination index, average growth index and sustenance index, respectively, of Trigonella foenum-graecum Linn. in treated soils was observed, compared to untreated soils. Thus, this study confirmed that microbes in ‘Consortial Union’ serve as better treating agents in bioremediation of oil-contaminated soils than individual microorganisms.

The increasing industrial demand for remediating the textile wastewater in an effective way has led to the pervasive acceptance of bioremediation. Bioremediation techniques such as bioaccumulation, biosorption, bioaugmentation, and biodegradation utilize the biological systems to treat the textile effluents containing the recalcitrant dye molecules. Bioremediation is known to be environmentally reliable and is an alternative to the conventional decomposition techniques with the prerequisite to fulfill the efficacy and economic viability. Among the aforementioned bio-remedial measures, biodegradation of the textile dyes is the trustworthy industrial application. Biodegradation of dyes can be achieved using single bacterial strains and co-cultures/consortia. The consortial systems are proven to be advantageous over a single strain as they involve an inductive synergistic mechanism among the co-existing strains. As a result of this co-metabolism, there is a formation of different intermediate metabolites such as toxic aromatic amines which are furthermore mineralized by the other bacterial strains in the consortia.

A field-scale study was conducted in a 4000 m2 plot of land contaminated with an oily sludge by use of a carrier-based hydrocarbon-degrading bacterial consortium for bioremediation. The land belonged to an oil refinery. Prior to this study, a feasibility study was conducted to assess the capacity of the bacterial consortium to degrade oily sludge. The site selected for bioremediation contained approximately 300 tons of oily sludge. The plot was divided into four blocks, based on the extent of contamination. Blocks A, B, and C were treated with the bacterial consortium, whereas Block D was maintained as an untreated control. In Block A, at time zero, i.e., at the beginning of the experiment, the soil contained as much as 99.2 g/kg of total petroleum hydrocarbon (TPH). The application of a bacterial consortium (1 kg carrier-based bacterial consortium/10 m2 area) and nutrients degraded 90.2% of the TPH in 120 days, whereas in block D only 16.8% of the TPH was degraded. This study validates the large-scale use of a carrier-based bacterial consortium and nutrients for the treatment of land contaminated with oily sludge, a hazardous hydrocarbon waste generated by petroleum industry.

Chapter 6 - Microbial consortium for bioremediation of polycyclic aromatic hydrocarbons polluted sites

Microorganisms are very important in biodegradation of edible oil contaminated effluents, and they find an excellent scope in restaurant wastewater bioremediation. The edible oil in such wastewater harms the environment in a number of ways. The native bacteria in the wastewater are less effective in degrading edible oil. It leads to the formation of blockage along the sewer line. This narrows the diameter of line and forms partial to complete blockage causing overflows of wastewater exposing humans and animals to diverse pathogens. A consortium of lipolytic bacteria and lipase enzyme gives a new approach for effective and environment friendly degradation of waste oil in restaurant wastewater. In the present study, the lipase produced by Pseudomonas aeruginosa VSJK-R9 isolated from restaurant wastewater was purified by ammonium sulfate precipitation, dialysis and gel exclusion chromatography-Sephadex G-100, with 11.45-fold purification to obtain a yield of 35.08%. Its molecular mass was around 50kDa as determined by SDS-PAGE analysis. The bioremediation of restaurant wastewater supplemented with 0.5% NH4Cl and 0.8% K2HPO4 was studied with lipolytic consortium formed by the combination of lipolytic isolates Acinetobacterjunii VSJK-R6, Pseudomonas compostiVSJK-R8 and Pseudomonas aeruginosa VSJK-R9. Further, the impact of lipase supplementation was also evaluated, and it was found that the action of consortium was boosted by lipase. The oil and chemical oxygen demand value of the restaurant wastewater was considerably decreased. These findings have shown the application of lipase for bioremediation of restaurant wastewater and its positive impact on the performance of lipolytic consortium.