Bioremediation Of Wastes Research Articles

English

Insect farming as food and feed has gained popularity. Insects require less land and water and are efficient in feed-food conversion, making them a sustainable alternative source of protein for food fortification and feed formulation. Some insects play a vital role in bio-remediation of organic waste as they feed on waste breaking it down to frass that has the potential to be used as an organic fertilizer in food production. Insects therefore, have great potential to contribute to climate-smart farming. This research explored the potential of cricket frass as an organic fertilizer for growing Cleome gynandra. Different levels of cricket frass and cow manure were as follows: 10, 15, and 20 t/ha; 100, 150, and 200 kg/ha of Di-ammonium Phosphate (DAP) and a control (no fertilizer) were used for the experiments. One experiment was sent in a controlled environment inside a greenhouse and a second one in the open field. In the greenhouse, Completely Block Design (CBD) was used while in the open field Randomized Complete Block Design (RCBD) was used. Parameters observed were plant height, number of leaves and biomass weight. Results showed that crops treated with frass gave longest plants, most number of leaves and had the heaviest biomass weight. Key words: Organic farming, frass, chemical fertilizer, small-scale farmers.

12 TEXTILE DYES DECOLORIZATION BY COPPER-RESISTANT-BACTERIA KLEBSIELLA GRIMONTII, SHIGELLA FLEXNERI, ENTEROBACTER CLOACAE ISOLATED FROM CISADANE RIVER TANGERANG

Dyes and copper are dangerous contaminants because they are toxic. Bioremediation using indigenous bacteria is the best solution to overcome water pollution. Copper resistant bacteria usually have resistance to dyes thereby helping the bioremediation of dye and copper wastes. This study aims to examine the ability of indigenous bacteria isolated from the Cisadane River, namely Klebsiella grimontii IrCis3, Shigella flexneri IrCis5, Enterobacter cloacae IrCis6, and Enterobacter cloacae IrCis9 in terms of resistance and ability to decolorize 12 textile dyes namely methylene blue, malachite green, congo red, mordant orange, reactive black, direct yellow, basic fuchsin, reactive orange, dispersed orange, remasol red, wantex yellow and wantex red. The results showed that Shigella flexneri IrCis5, Enterobacter cloacae IrCis6, and Enterobacter cloacae IrCis9 were resistant to all dye concentrations of 200 and 500 ppm except Klebsiella grimontii IrCis3 did not grow on malachite green and basic fuchsin at concentrations of 200 ppm and methylene blue, malachite green and basic fuchsin concentration of 500 ppm. Only Shigella flexneri IrCis5 has the ability to decolorize 200 ppm basic fuchsin up to 87.23% after 3 days of incubation. The addition of 3 mM CuSO4 reduced the ability to decolorize Shigella flexneri IrCis5 to 0.57%.

A sulfide-sensor and a sulfane sulfur-sensor collectively regulate sulfur-oxidation for feather degradation by Bacillus licheniformis

Bacillus licheniformis MW3 degrades bird feathers. Feather keratin is rich in cysteine, which is metabolized to produce hazardous sulfide and sulfane sulfur. A challenge to B. licheniformis MW3 growing on feathers is to detoxify them. Here we identified a gene cluster in B. licheniformis MW3 to deal with these toxicity. The cluster contains 11 genes: the first gene yrkD encodes a repressor, the 8th and 9th genes nreB and nreC encode a two-component regulatory system, and the 10th and 11th genes encode sulfide: quinone reductase (SQR) and persulfide oxygenase (PDO). SQR and PDO collectively oxidize sulfide and sulfane sulfur to sulfite. YrkD sensed sulfane sulfur to derepress the 11 genes. The NreBC system sensed sulfide and further amplified the transcription of sqr and pdo. The two regulatory systems synergistically controlled the expression of the gene cluster, which was required for the bacterium to grow on feather. The findings highlight the necessity of removing sulfide and sulfane sulfur during feather degradation and may help with bioremediation of feather waste and sulfide pollution.

Green synthesis of copper oxide nanoparticles using Ephedra Alata plant extract and a study of their antifungal, antibacterial activity and photocatalytic performance under sunlight

In the present work, copper oxide (CuO NPs) was synthesized by an eco-friendly, simple, low-cost, and economical synthesis method using Ephedra Alata aqueous plant extract as a reducing and capping agent. The biosynthesized CuO-NPs were compared with chemically obtained CuO-NPs to investigate the effect of the preparation method on the structural, optical, morphological, antibacterial, antifungal, and photocatalytic properties under solar irradiation. The CuO NPs were characterized using X-ray diffraction (XRD), UV-VIS spectroscopy, Fourier transform infrared spectrometer (FTIR) analysis, and field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX). The photocatalytic activities of biosynthetic CuO-NPs and chemically prepared CuO-NPs were studied using methylene blue upon exposure to solar irradiation. The results showed that the biosynthesized CuO photocatalyst was more efficient than the chemically synthesized CuO-NPs for Methylene Blue (MB) degradation under solar irradiation, with MB degradation rates of 93.4% and 80.2%, respectively. In addition, antibacterial and antifungal activities were evaluated. The disk diffusion technique was used to test the biosynthesized CuO-NPs against gram-negative bacteria, Staphylococcus aureus and Bacillus subtilis, as well as C. Albicans and S. cerevisiae. The biosynthesized CuO-NPs showed efficient antibacterial and antifungal activity. The obtained results revealed that the biosynthesized CuO-NPs can play a vital role in the destruction of pathogenic bacteria, the degradation of dyes, and the activity of antifungal agents in the bioremediation of industrial and domestic waste.

Evaluating sea cucumbers as extractive species for benthic bioremediation in mussel farms

Filter-feeding mussels blend suspended particles into faeces and pseudo-faeces enhancing organic matter flows between the water column and the bottom, and strengthening benthic-pelagic coupling. Inside operating farms, high bivalve densities in relatively confined areas result in an elevated rate of organic sinking to the seabed, which may cause a localized impact in the immediate surrounding. Deposit-feeding sea cucumbers are potentially optimal candidates to bioremediate mussel organic waste, due to their ability to process organic-enriched sediments impacted by aquaculture waste. However, although the feasibility of this polyculture has been investigated for a few Indo-Pacific species, little is known about Atlanto-Mediterranean species. Hence, for the first time, in the present study, we conducted a comparative investigation on the suitability of different Mediterranean sea cucumber species, to be reared in Integrated Multitrophic Aquaculture (IMTA) with mussels. A pilot-scale experiment was accomplished operating within a mussel farm where two sea cucumbers species, Holothuria tubulosa and Holothuria polii, were caged beneath the long-line mussel farm of Mytilus galloprovincialis. After four months, H. tubulosa showed high survivorship (94%) and positive somatic growth (6.07%); conversely H. polii showed negative growth (− 25.37%), although 92% of specimens survived. Furthermore, sea cucumber growth was size-dependent. In fact, smaller individuals, independently from the species, grew significantly faster than larger ones. These results evidenced a clear difference in the suitability of the two sea cucumber species for IMTA with M. galloprovincialis, probably due to their different trophic ecology (feeding specialization on different microhabitats, i.e. different sediment layers). Specifically, H. tubulosa seems to be an optimal candidate as extractive species both for polycultures production and waste bioremediation in M. galloprovincialis operating farms.

Applications of Actinobacteria in aquaculture: prospects and challenges.

Disease outbreaks due to improper culture management, poor water quality, and climate change are major concerns in aquaculture. Most of the aquatic pathogens are opportunistic and any imbalance in the host-pathogen-environment triad will result in a disease outbreak. The indiscriminate use of chemotherapeutics such as antibiotics to prevent diseases in aquaculture will lead to antimicrobial resistance in aquaculture. Hence, the demand for natural microbial strains which can be used as beneficial probiotics and bioaugmentors in fish farming systems has increased to ensure one health in aquaculture. Studies have proved the probiotic and bioremediation potential of several Actinobacterial species that can be applied in aquaculture. Actinobacteria, especially Streptomyces, can be applied in aquaculture for disease prevention, treatment, and bioremediation of organic and inorganic waste in the culture systems. The growth, immunity, and resistance towards aquatic pathogens in cultured organisms also get enhanced through their capability to release potent antimicrobial compounds, bioactive molecules, and novel enzymes. Their broad-spectrum antimicrobial and quorum quenching activity can be well exploited against quorum sensing biofilm forming aquatic pathogens. Even though they impart specific adverse effects like the production of off-flavour compounds, this could be controlled through proper management strategies. This review discusses the applications, challenges, and prospects of Actinobacteria in aquaculture. Research gaps are also highlighted, which may shed light on the existing complexities and should pave the way for their better understanding and utilisation in aquaculture.

Bioremediation of Hazardous Wastes Using Green Synthesis of Nanoparticles

Advanced agronomic methods, urbanisation, and industrial expansion contaminate air, water and soil, globally. Agricultural and industrial activities threaten living biota, causing biodiversity loss and serious diseases. Strategies such as bioremediation and physiochemical remediation have not been effectively beneficial at treating pollutants. Metal-based nanoparticles (NPs) such as copper, zinc, silver, gold, etc., in various nanoformulations and nanocomposites are used more and more as they effectively resist the uptake of toxic compounds via plants by facilitating their immobilisation. According to studies, bio-based NP synthesis is a recent and agroecologically friendly approach for remediating environmental waste, which is effective against carcinogens, heavy metal contamination, treating marine water polluted with excessive concentrations of phosphorus, nitrogen and harmful algae, and hazardous dye- and pesticide-contaminated water. Biogenic resources such as bacteria, fungi, algae and plants are extensively used for the biosynthesis of NPs, particularly metallic NPs. Strategies involving green synthesis of NPs are nontoxic and could be employed for commercial scale production. Here, the focus is on the green synthesis of NPs for reduction of hazardous wastes to help with the clean-up process.

Microbial assemblage for solid waste bioremediation and valorization with an essence of bioengineering.

Environmental solid waste bioremediation is a method of treating contaminated solid waste that involves changing ecological conditions to foster the growth of a broad spectrum of microorganisms and the destruction of the target contaminants. A wide range of microorganisms creates metabolites that may break down and change solid waste-based pollution to various value-added molecules. Diverse bioremediation technologies, their limitations, and the procedure involve recycling solid waste materials from the environment. The existing environmental solid waste disposal services are insufficient and must be upgraded with more lucrative recovery, recycling, and reuse technologies to decrease the enormous expenditures in treatment procedures. Bioremediation of solid waste eliminates the toxic components. It restores the site with the advent of potential microbial communities towards solid waste valorization utilizing agriculture solid waste, organic food waste, plastic solid waste, and multiple industrial solid wastes.Bioengineering on diverse ranges of microbial regimes has accelerated to provide extra momentum toward solid waste recycling and valorization. This approach increases the activity of bioremediating microbes in the commercial development of waste treatment techniques and increases the cost-effective valuable product generation. This framework facilitates collaboration between solid waste and utilities. It can aid in establishing a long-term management strategy for recycling development with the advent of a broad spectrum of potential microbial assemblages, increasing solid waste contamination tolerance efficiency and solid waste degradability. The current literature survey extensively summarises solid waste remediation valorization using a broad spectrum of microbial assemblages with special emphasis on bioengineering-based acceleration. This approach is to attain sustainable environmental management and value-added biomolecule generation.

Microbial Fuel Cell as New Renewable Energy for Simultaneous Waste Bioremediation and Energy Recovery

Microbial fuel cell (MFC) is an outstanding technology recently creating the headlines relating to energy and environment field that been discovered since the earlier 20th century. It has been furthered implemented for energy renewable through simultaneous bioremediation of wastes. MFC works by converting chemical energy store in the waste into electrical energy with the help of selected microorganisms. Regarding to this, the principle of bioremediation was applied using MFC as the renewable energy where the microorganisms consume the substrate thus generating electrical energy. Many studies done by researches are mostly focusing on MFC utilizing waste and measuring the power generation on different type of MFC but lack of studies on the effect of series and parallel circuit in MFC setup and how does it differentiate the outcome of the studies. This paper reviews the history, working principle, design of MFC, classification of different substrates and its power output and the effect of series and parallel circuit of MFC setup for simultaneous bioremediation and energy recovery.

Isolation, antibacterial screening, and identification of bioactive cave dwelling bacteria in Fiji.

Bacteria are well known producers of bioactive secondary metabolites, including some of the most effective antibiotics in use today. While the caves of Oceania are still largely under-explored, they form oligotrophic and extreme environments that are a promising source for identifying novel species of bacteria with biologically active compounds. By using selective media that mimicked a cave environment, and pretreatments that suppressed the growth of fast-growing bacteria, we have cultured genetically diverse bacteria from a limestone cave in Fiji. Partial 16S rRNA gene sequences from isolates were determined and compared with 16S rRNA gene sequences in EzBioCloud and SILVA data bases. Fifty-five isolates purified from culture had Actinomycete-like morphologies and these were investigated for antibacterial activity. Initial screening using a cross streak test with pathogenic bacteria indicated that 34 of the isolates had antibacterial properties. The best matches for the isolates are bacteria with potential uses in the manufacture of antibiotics and pesticides, in bioremediation of toxic waste, in biomining, in producing bioplastics, and in plant growth promotion. Nineteen bacteria were confirmed as Actinomycetes. Thirteen were from the genus Streptomyces and six from genera considered to be rare Actinomycetes from Pseudonocardia, Kocuria, Micromonospora, Nonomuraea. Ten isolates were Firmicutes from the genera Bacillus, Lysinbacillus, Psychrobacillus and Fontibacillus. Two were Proteobacteria from the genera Mesorhizobium and Cupriavidus. Our findings identify a potentially rich source of microbes for applications in biotechnologies.

The influence on microorganisms of heavy metals from refiner’s spent desulphurisation catalysts

ABSTRACT Refinery wastes generated in conventional crude oil refining processes, or in accidental situations, are complex substrates for treatment and disposal. Petroleum desulphurisation catalysts can also be hazardous refinery waste. They contain various metals, such as cobalt, molybdenum, nickel and tungsten. In this paper, three petroleum refiner’s spent desulphurisation catalysts were investigated. These catalysts were not suitable for recycling and, therefore, were classified as hazardous waste. They were chemically characterised, including phase composition and their effect on a consortium of microorganisms used in the process of bioremediation. Catalysts contained up to 2.26 g kg−1 of total petroleum hydrocarbons, up to 56.7 g kg−1 of iron, 18.6 g kg−1 of molybdenum, and less than 0.1 mg kg−1 each of cobalt and nickel. These obtained results show that bioremediation of such waste is possible.

Effective valorization of precision output of algaquaculture towards eco-sustainability and bioeconomy concomitant with biotechnological advances: An innovative concept

Both input resources and ecosystem stability are critical to the long-term viability and sustainability of the aquaculture business, which is booming while supporting global food security. Over the past few decades, technical advancements have been made to help achieve both economic and environmental goals. Among these, “algaquaculture,” which combines algae culture with aquaculture, is seen as a revolutionary concept with numerous advantages. The only difference between this system and aquaponics is that algae are used instead of leafy plants. In aquaponic systems, this integration is innovative because of algae’s superior ability to utilize waste-derived nutrients, such as nitrate, nitrite, and total ammonia nitrogen (TAN). An additional benefit of algae is that they promote growth, stimulate the immune system, and even enhance the color of fish. Some algae with human health benefits and biodiesel sources have a high market price, which can be used to compensate for an integrated aquaculture-based system’s higher economic value. While aquaculture waste bioremediation can greatly improve environmental sustainability, it is important to note that algae can play a significant part in bioremediation because of their ability to minimize environmental disruptions. This review aims to highlight the new concept of algaquaculture, functional role of algae in aquaculture, and biotechnological advancements for the bioeconomy to establish microalgae-based food production systems, including aquaculture, by citing the role and benefits of such an integrated algal-aquaculture system. For this reason, the review intends to disseminate an idea like this over the globe, focusing on how to preserve the sector in the coming years. • Algaquaculture, which combines algae culture with aquaculture, is seen as a revolutionary concept with numerous advantages. • Algaquaculture has great impact on circular and bioeconomy. • The biotechnological advances makes algaquaculture a sustainable strategy for frontiers industrial applications.

THE APPLICATION OF ENDOSCOPE AND IMAGE PROCESSING FOR DETERMINING REMAZOL RED DYE CONCENTRATION IN WATER SAMPLES

Remazol dyes are widely used in textile industry, which are then discharged to the environment as waste products. Studies on bioremediation and decolorization of dye waste normally employ expensive spectrometers or colorimeters. This study proposes a low-cost procedure to determine the concentration of Remazol red dye with the use of a digital endoscope and image processing technique. The concentration of Remazol red dye considered in this study ranges from 0.001 to 0.700 g/L. An endoscope is used to capture digital images of dye samples. Reg-green-blue (RGB) images of the samples are converted to grayscale images, which are then converted to a mean grayscale index (MGI). The MGI is then calibrated with real concentration of dye samples. Three calibration curves were developed for three different ranges of dye concentration of 0.001- 0.010 g/L, 0.020 – 0.100 g/L, and 0.100 – 0.700 g/L, with a coefficient of determination (R2) of 0.961, 0.9793, and 0.9903, respectively.

Critical Review on Nanomaterials for Enhancing Bioconversion and Bioremediation of Agricultural Wastes and Wastewater

Anaerobic digestion (AD), microalgae cultivation, and microbial fuel cells (MFCs) are the major biological processes to convert organic solid wastes and wastewater in the agricultural industry into biofuels, biopower, various biochemical and fertilizer products, and meanwhile, recycle water. Various nanomaterials including nano zero valent irons (nZVIs), metal oxide nanoparticles (NPs), carbon-based and multicompound nanomaterials have been studied to improve the economics and environmental sustainability of those biological processes by increasing their conversion efficiency and the quality of products, and minimizing the negative impacts of hazardous materials in the wastes. This review article presented the structures, functionalities and applications of various nanomaterials that have been studied to improve the performance of AD, microalgae cultivation, and MFCs for recycling and valorizing agricultural solid wastes and wastewater. The review also discussed the methods that have been studied to improve the performance of those nanomaterials for their applications in those biological processes.

Structural, functional, and molecular docking analyses of microbial cutinase enzymes against polyurethane monomers

Plastic waste is the biggest global problem in present times due to its constant bioaccumulation in the environment. During the last year, 367 Mt of plastics were produced in the world, of which 28.6 Mt correspond to polyurethane waste. Polyurethanes can be found in products such as adhesives, preservatives, and foams, and are often difficult to recycle. The fragmentation of plastic waste in the environment generates microplastics causing a long-term effect on our ecosystem. In search of its solution via bioremediation using enzymes, in our present study cutinase enzyme has been chosen, as it appears to be a novel candidate due to the wide variety of substrates it hydrolyzes and its presence in different microorganisms. According to physiochemical characteristics, it was found that microbial cutinase enzymes are majorly made up of aliphatic amino acids. A higher aliphatic index (more than 80) indicates the great thermostability of the enzyme. Moreover, the enzyme is found to be hydrophilic and structurally stable. The negative GRAVY value of the enzyme confirmed its stable interaction with water. It was also observed that all chosen protein models had an average of 91.10 % amino acids in the favorable regions of the Ramachandran plot. The studied microbial cutinase enzymes from both fungi Humicola insolens and actinobacterium Thermobifida fusca successfully coupled with the polyurethane resin monomers. The main interactions were found in the catalytic triad with bonds close to the urethane bonds of the ligand, in addition to having an average binding energy of − 6 kJ/mol. The interaction between the cutinases with the PUR resin as a ligand was found to be evident from our study with stable binding energies, which makes microbial cutinases potential enzymes for polyurethane waste bioremediation processes.

Co-metabolism of 4-bromophenol by Pseudomonas sp. EN-4 and toxicity evaluation of biotransformed samples

Bromophenols, the building blocks of polybrominated flame retardants (PBFRs) constitute an important class of pollutants as they had been reported from different types of ecosystems across the earth. The improper disposal of PBFRs containing electronic waste (e-waste) and wastes from industrial units is of concern due to their recalcitrant nature and acute toxicity. In the current study Pseudomonas sp. EN-4 was able to metabolise 4-bromophenol (4-BP), a model representative of bromophenols in presence of phenol as a co-substrate. The isolate withstand the extreme pH (5.0–10.0) and salinity conditions (0.5–2% w/v) and maintain its degradation potential in presence of different metal ions prevalent at contaminated sites. The HPLC and MS analysis of biotransformed samples revealed the formation of catechol, which might get channelized to the central metabolic pathway by catechol 1,2-dioxygenase mediated ortho-cleavage of the aromatic ring. Further, > 70 % transformation of 2-bromophenol (20 mg/L), 2,4,6-tribromophenol (20 mg/L) and 3,3’,5,5′-tetrabromobisphenol A (10 mg/L) indicates the metabolic versatility of strain EN-4. A significantly lower toxic potential of biologically treated samples on Vigna radiata and Channa punctatus validated the utility and efficacy of EN-4 cells. These findings lay the foundation for future studies in developing a site specific treatment system for bioremediation of waste generated by e-waste processing and other similar units.

A waste-to-wealth initiative exploiting the potential of Anabaena variabilis for designing an integrated biorefinery.

The current research work was an innovative approach providing dual advantages of waste bioremediation and an effective biorefinery. The study attempted to exploit wastewater like aqua discharge and solid wastes like poultry litter/cow dung for cyanobacterial cultivation. Aqua discharge appended with 7.5 g L−1 poultry litter turned out as the best combination generating 46% higher carbohydrate yield than BG-11 control. A. variabilis cultivation in this waste-utilized medium also revealed its excellent bioremediation ability. While 100% removal was observed for nitrite, nitrate, and orthophosphate, a respective 74% and 81% reduction was noted for ammonium and total organic carbon. Chemical and biological oxygen demands were also reduced by 90%. This work was also novel in developing a sequential design for the production of bioethanol and co-products like exopolysaccharides, sodium copper chlorophyllin, C-phycocyanin, and poly-β-hydroxybutyrate from the same cyanobacterial biomass. The developed biorefinery implementing the waste-utilized medium was one of its kind, enabling biomass valorization of 61%. Therefore, the present study would provide a leading-edge for tackling the high production costs that limit the practical viability of biorefinery projects. The recyclability of the bioremediated wastewater would not only curtail freshwater usage, the waste disposal concerns would also be mitigated to a great extent.

Biodegradation of polyethylene based films used in water packaging by dumpsite bacteria

Water sachet bags are Low-density polyethylene (LDPE) based polymers that are of widespread use in Nigeria. The accumulation of these sachet bags has resulted to severe environmental pollution. Microorganisms have been found to provide an eco-friendly and practical alternative to conventional methods in the clean-up of LDPE wastes in the environment. This study investigated the potentials of six bacteria strains Lysinibacillus xylanilyticus PE4, Pseudomonas aeruginosa PE2, Pseudomonas aeruginosa S1, Stenotrophomonas maltophilia S6, Pseudomonas aeruginosa W5 and Achromobacter xylosoxidans strain to degrade water sachet films. The degradation was monitored for a period of 56 days in vitro and the extent of degradation was measured using Fourier transform infrared spectroscopy and scanning electron microscopy coupled with EDX. FTIR spectroscopy analysis of the bacteria treated LDPE samples revealed changes in functional groups of LDPE samples as a result of hydrolysis and oxidation of bonds in the LDPE polymer. Also, the EDX elemental analysis of the treated LDPE and the untreated control showed a reduction in percentage elemental carbon and increase in the elemental oxygen of the treated LDPE films which is evident of degradation. The findings indicate strongly the degradation potentials of these bacteria strains on LDPE polymer, they therefore show significant promise for bioremediation of plastic wastes.

Use of black soldier fly (Hermetia illucens) prepupae reared on organic waste as feed or as an ingredient in a pellet-feed formulation for Nile tilapia (Oreochromis niloticus).

The growth and sustainability of freshwater aquaculture are highly dependent on economic feed which is the major running cost. Fish feed industries depend on the high-priced fish meal (FM) as protein source in feed formulations. In this context, a nutrient-rich, and palatable insect meal-based fish feed was developed incorporating the black soldier fly (BSF) (Hermetia illucens) prepupae meal (BSFPM) reared on organic waste imparting additional benefit of waste bioremediation to make cost-effective feed. Feeding trial was conducted to evaluate growth performance on monosex Nile tilapia (Oreochromis niloticus). The different treatments were (1) dried BSF prepupae, (2) BSF prepupae and BSFPM-based feed in 1:1 proportion, (3) BSFPM feed, and (4) control feed with FM. The survival, growth, feed efficiency, and haematological parameters were not significantly different between BSFPM and control feed. Fish fed with control feed and BSFPM feed showed significantly higher (P ≤ 0.05) weight gain, specific growth rate, and percentage weight gain. Lowest food conversion ratio (P ≤ 0.05) was recorded for fish fed control feed with a significantly higher feed efficiency ratio (0.65d ± 0.034) and protein efficiency ratio (2.11a ± 0.063). The mean corpuscular volume of blood in fish fed BSF prepupae (128.5a ± 3.2) is significantly higher. The good growth of fish fed BSFPM feed may be attributed to the essential amino acids which are not limiting in feed. Absence of microbes and safe level heavy metals in BSFPM feed ensures safety of the ingredient. Hence, it can be used as a suitable protein source in feed formulations.

Burkholderia cepacia strain IrV1 multi-resistant to copper and dyes isolated from laboratory wastewater effluent

Abstract. Irawati W, Lindarto V, Pinontoan R, Yuwono T, Mangunsong FM, Silalahi DW. 2022. Burkholderia cepacia strain IrV1 multi-resistant to copper and dyes isolated from laboratory wastewater effluent. Biodiversitas 23: 2614-2620. Copper and dye multi-resistant bacteria may be cultivated to increase the efficiency of waste bioremediation processes. Multi-resistant bacteria can be isolated from waste containing copper and dyes, including laboratory waste. The aims of this study were to: (i) isolate copper-resistant bacteria from wastewater, (ii) determine the multi-resistance of bacteria against copper and dyes, and (iii) observe the ability of bacteria to remove colors methylene blue, basic fuchsin, and Congo red. Selected bacterial isolates were identified based on the 16S rDNA gene. One highly copper resistant bacterial strain IrV, showed resistance to 7 mM CuSO4, 100 ppm methylene blue, 100 ppm basic fuchsin, and 100 ppm Congo red. Based on the 16S rDNA gene sequence, strain IrV belongs to Burkholderia cepacia with 99.86% similarity. The addition of copper on the medium resulted in colony color changes from light yellow to green indicated Cu binding within the cell. Moreover, a clear zone around the colony was observed, suggesting that the strain is capable of decolorizing methylene blue, Congo red, and basic fuchsin dyes. The results thus demonstrate that bacterial strain IrV is multi-resistant to copper and dyes.