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The production of extremozymes from halophilic bacteria has increased significantly due to their stability and efficiency in catalyzing a reaction, as well as their capacity to display optimum activity at various salt concentrations. In the current study, the halophilic bacterium Virgibacillus salarius strain BM-02 could utilize many non-pretreated substrates including cellulose, corn stover, sugarcane bagasse and wheat bran as a sole carbon source. However, wheat bran was the best substrate for achieving optimum saccharification yield (90.1%). The partially purified cellulase was active and stable at a wide range of pH (5–8) with residual activities > 58%. Moreover, it was stable at 5–12% of NaCl. Metal ions have a variable impact on the activity of partially purified cellulase however, Fe+3 exhibited the highest increase in the cellulase activity. The enzyme exhibited a thermal stability at 40, 50 and 60 °C with half-lives of 1049.50, 168.14 and 163.5 min, respectively. The value of Vmax was 22.27 U/mL while Km was 2.1 mM. The activation energy of denaturation Ed 69.81 kJ/mol, the enthalpy values (ΔHd) were positive, and the entropy values (ΔS) were negative. Therefore, V. Salarius is recommended as a novel promising halophilic extremozyme producer and agricultural waste remover in the bio-industrial applications. Graphical abstract

In this study, development biofertilizer is produced from sugarcane residues was compared with commercial biological fertilizers. Development Fertilizers from sugarcane wastes have been analyzed chemically and microbiologically. Factors affecting the ripening of the compost and growth of microorganisms in the dander, (temperature, humidity and pH) were monitored. The final values ​​for each were 45, 30 and 8., respectively. The compost ripening was followed by the analysis of organic matter and organic carbon, their respective values were 20.7 and 63.54, respectively, and the C: N ratio was 1:16 upon completion of ripening. The ratio of major elements N, P, K, which was 2.4, 4.78 And 0.06 respectively at the end of the ripening period. Bacterial isolated from sugarcane wastes were belonged to Bacillus genera, while fungal isolates belonged to Aspergillus genera.

Investigation of an alternative source of the nonrenewable energy is attracting the world attention nowadays. The fruits and leaves biomass of Calotropis procera were exposed to sequential pretreatment processes. First, a successive pretreatment with an organic solvent (hexane/methanol) yielded biocrude and plant spent residues fractions. The plant spent residues fractions were exposed to successive acid/alkali (1% H2SO4/2% NaOH) pretreatment to yield spent residues of fruits (SRF) and leaves (SRL). The amount of cellulose content of the sequential pretreated SRF and SRL were 87.3 and 83.4%, respectively. The hydrolysis process of 10 g of the sequential pretreated SRF and SRL by Sternzym cellulase produced 80.2 and 50.4 g/L of total reduced sugars, respectively. The reduced sugars were then fermented by Saccharomyces cerevisiae (MN901244) for bioethanol production. The HPLC analysis showed 38.9 and 23.8 g/L of bioethanol yields from sequential pretreated SRF and SRL, respectively. The GC/MS analysis of methanol and hexane biocrude fractions revealed the presence of 20 and 12% of fatty acids, respectively, which would be promising amounts for biodiesel production after esterification. So, the present study suggested a low-cost nonedible plant biomass (Calotropis procera) as a biorefinery for production of renewable bioethanol.

The xylanolytic and amylolytic yeasts were qualitatively determined by Cong red xylan agar and soluble starch agar plates, respectively. The most xylanase and α-amylase inducible strain (AUN-02) was selected and identified using PCR amplification of 26S rRNA gene and sequence analysis. The comparison of the alignment results and phylogenetic analysis of the sequences of the isolated yeast to published rRNA gene sequences in GenBank, confirmed the identification of the isolate as Pichia membranifaciens. Xylanase and α-amylase production by isolated P. membranifaciens were investigated at different pH values (4-8), temperature degrees (20-45°C), incubation time (1-7 days) and various substrates.A higher production of xylanase (38.8 U/mL) and a-amylase (28.7 U/mL) was obtained after 4 days of fermentation of P. membranifaciens. Higher activity of xylanase (36.83 U/mL) and a-amylase (27.7 U/mL) was obtained in the fermentation of P. membranifaciens in a culture medium adjusted to pH 7.0. The optimum temperature showed maximum xylanase and a-amylase activity (42.6 and 32.5 units/mL, respectively) was estimated at 35 °C. The xylanase and a-amylase activities of P. membranifaciens were estimated and compared for the different substrates tested. The strain revealed 100% relative activity of xylanase and a-amylase on beechwood and potato starch, respectively. The affinity of enzymes towards substrate was estimated using Km values. The Km values of xylanase and α-amylase increased in the order of pH’s 7.0, 6.0 and 4.5 (0.85, 1.6 and 3.4 mg xylan/mL and 0.22, 0.43 and 2.8 mg starch/mL, respectively). the yeast P. membranifaciensis is suitable for produce neutral xylanase and α-amylase enzymes. So, it could be used as a promising strain for production of these enzymes in industrial field.

Background: Petroleum polycyclic aromatic hydrocarbons (PAHs) are known to be toxic and carcinogenic for humans and their contamination of soils and water is of great environmental concern. Identification of the key microorganisms that play a role in pollutant degradation processes is relevant to the development of optimal in situ bioremediation strategies. Objective: Detection of the ability of Pseudomonas fluorescens AH-40 to consume phenanthrene as a sole carbon source and determining the variation in the concentration of both nahAC and C23O catabolic genes during 15 days of the incubation period. Methods: In the current study, a bacterial strain AH-40 was isolated from crude oil polluted soil by enrichment technique in mineral basal salts (MBS) medium supplemented with phenanthrene (PAH) as a sole carbon and energy source. The isolated strain was genetically identified based on 16S rDNA sequence analysis. The degradation of PAHs by this strain was confirmed by HPLC analysis. The detection and quantification of naphthalene dioxygenase (nahAc) and catechol 2,3-dioxygenase (C23O) genes, which play a critical role during the mineralization of PAHs in the liquid bacterial culture were achieved by quantitative PCR. Results: Strain AH-40 was identified as pseudomonas fluorescens. It degraded 97% of 150 mg phenanthrene L-1 within 15 days, which is faster than previously reported pure cultures. The copy numbers of chromosomal encoding catabolic genes nahAc and C23O increased during the process of phenanthrene degradation. Conclusion: nahAc and C23O genes are the main marker genes for phenanthrene degradation by strain AH-40. P. fluorescence AH-40 could be recommended for bioremediation of phenanthrene contaminated site.

Contamination of water with Malachite green (MG) may threaten aquatic and human life. Nitrogen-fixing Azotobacter sp. is an efficient adsorbent for the removal of MG from dye solutions. The optimum pH for the biosorption process was determined. The maximum adsorption capacity and the effect of different adsorbate concentrations were detected. The kinetics and isotherm models for biosorption were constructed. Optimum adsorption of MG by Azotobacter sp. was obtained at pH 6.0, biomass concentration was 0.05%, initial dye concentration was 50 mg.L-1, and contact time was 600 mins. Dye adsorption exhibited an increase with contact time and initial malachite green concentration. The kinetics of the adsorption process was best followed by the pseudo-second-order kinetic model which confirms the chemisorption process. The adsorption equilibrium data fit well to the Langmuir model indicating a monolayer adsorption behavior onto a surface of Azotobacter sp. with a finite number of active sites. Maximum biosorption capacity was found to be 142.8 mg.g-1 of bacterial biomass. The dry biomass of Azotobacter sp. has proved to be an efficient biosorbent for the removal of synthetic dyes from actual industrial effluent that is contaminated with up to 400 mg.L-1 dye concentration.

AIMS The major aims of this study are to determine the capability of sulphur oxidizing bacterium (SOB-1) to desulphurize dibenzothiophene (DBT) and crude oil, detection of the reaction kinetics and identify the proposed pathway of DBT desulphurization. METHODS AND RESULTS The isolate was genetically identified based on 16S rRNA gene sequencing as Klebsiella oxytoca and deposited in the Genebank database under the accession number: MT355440. The HPLC analysis of the remaining DBT concentration revealed that, SOB-1 could desulphurize 90% of DBT (0·25 mmol l-1 ) within 96 h. The maximum production of sulphate ions from the desulphurization of DBT (0·36 mmol l-1 ) and crude oil (0·4 mmol l-1 ) could be quantitatively detected after 48 h of incubation at 30°C. The high values of correlation coefficient (R2 ) obtained at all studied concentrations; suggested that biodesulfurization kinetics of DBT follows the first-order reaction model. The kinetics studies showed that, DBT may have an inhibitory effect on SOB-1 when the initial concentration exceeded 0·75 mmol l-1 . The GC-MS analysis exhibited four main metabolites rather than DBT. The most important ones are 2-hydroxybiphenyl (2-HBP) and methoxybiphenyl n(2-MBP). CONCLUSIONS Klebsiella oxytoca SOB-1 catalyzes the desulphurization of DBT through 4S pathway and forms four main metabolic products. The release of sulphate ion and formation of 2-HBP indicating the elimination of sulphur group without altering the carbon skeleton of DBT. The bacterial strain could also catalyzes desulphurization of crude oil. The desulphurization kinetics follows the first-order reaction model. SIGNIFICANCE AND IMPACT OF THE STUDY Klebsiella oxytoca SOB-1 could be used as a promising industrial and environmental biodesulfurizing agent as it is not affecting carbon skeleton of thiophenic compounds and forming less toxic metabolic product (2-MBP).

Polycyclic aromatic hydrocarbons (PAHs) are highly persistent compounds as well as they have a toxic impact to all living organisms. Removal of these xenobiotic compounds by mixed bacteria is achieving a maximum degradation rate over the pure strains. So, this study substantiates the application of constructed bacterial consortium for degradation of 400 mg/L phenanthrene within 30 days of incubation at 30 °C. The consortium consisted of two bacterial species Pseudomonas pseudoalcaligenes (B1) and Pseudomonas aeruginosa (B2). It exhibited a significantly higher phenanthrene degradation efficiency (97.5%) compared to pure strains B1 and B2 (52.5 and 47.6%), respectively. The phenanthrene degradation rate by the individual strains was enhanced in the presence of salicylic and phthalic acids as intermediates pathway. On the other side, the degradation rate was reduced in the presence of catechol suggesting a feedback inhibition of catabolic enzymes. The ring-cleavage dioxygenases were induced in all treatments. However, the induction of ortho cleavage dioxygenase (2.44 U/mg protein) was higher than meta cleavage dioxygenase (0.42 U/mg protein). Six main metabolites were detected by GC–MS analysis. Among them, four metabolites were detected in the extract of phenanthrene growing consortium suggesting three main pathways, phthalate, salicylic and benzocoumarin by the constructed consortium. Therefore, this study provides a measuring of phenanthrene degradation efficacy by bacterial consortium and paved the way to increase the potential of using the consortium for successful removal of PAHs from the polluted environment.

Microorganisms have an effective capability to degrade synthetic dyestuff enzymatically. In this study, two 16S rRNA identified Pseudomonas aeruginosa bacterial isolates (ASU3 and ASU6) have been screened to enzymatically degrade both Disperse Blue 64 (DB64) and Acid Yellow 17 (AY17) which resembles 2 of the synthetic dyes that causes aquatic environmental pollution. The expression of the azoR1 gene has been detected in the strains, the degradation percentage of DB64 and AY17 by stain ASU6 was found to exceed the ASU3. This returned to the differences in the expression levels of azoR1 between the ASU6 and the ASU3 which was confirmed by RT-PCR. In addition, the specific activity (U/mg protein) of azoreductase in ASU6 was higher than ASU3 when MethylRed (MR), DB64 and AY17 were used as a substrate, separately. The azoreductase kinetics was studied to find the optimum condition for maintaining the stability of the enzyme. The degraded products separated by HPLC/MS were tested for their toxicity on two crop plants and they were nontoxic to the plants. Keywords: Azoreductase, Kinetics, Pseudomonas aeruginosa, Synthetic dyes

Objectives:This study evaluates the ability of a non-white rot fungus strain, HESHAM-1, to degrade a mixture of low (naphthalene and phenanthrene) and high (chrysene and benzo(a)pyrene) molecular weight polycyclic aromatic hydrocarbons (LMW and HMW PAHs).Methods:Strain HESHAM-1 was isolated from oil polluted soil by enrichment method using phenanthrene as the sole source of carbon and energy. The strain showed the ability to tolerate and degrade a mixture of both low and high molecular weight PAHs. In the presences of LMW-PAHs (naphthalene and phenanthrene) as co-substrate, chrysene and benzo(a)pyrene (HMW-PAHs) were, respectively degraded by the fungus strain HESHAM-1 which was confirmed by GC-MS analyses.Results:The degradation rate was found as 84.82% for naphthalene, 40.09% for phenanthrene, 57.84% for chrysene and 71.06% for benzo(a)pyrene at the end of 10 days. This is the first report describing the biodegradation of a mixture of four PAH compounds by non-white rot fungus strain HESHAM-1 isolated from Egyptian oil-polluted soil. The fungus strain HESHAM-1 was identified by morphological characteristics and molecular genetics technique based on PCR amplification and sequencing of the internal transcribed spacers (ITSs) of the rDNA region and intervening 5.8S rRNA gene. Blast result and phylogenetic analysis of gene sequencing suggested that strain HESHAM-1 was closely related toFusarium solaniwith 100% sequence identity.Conclusion:The present study clearly demonstrates that, strain HESHAM-1 could be used to remove the crude oil from the environment.

Background: The presence of anthraquinone (Disperse blue 64) and azodyes (Acid yellow 17) in a waterbody are considered among the most dangerous pollutants. Methods: In this study, two different isolated microbes, bacterium and fungus, were individually and as a co-culture applied for the degradation of Disperse Blue 64 (DB 64) and Acid Yellow 17 (AY 17) dyes. The isolates were genetically identified based upon 16S (for bacteria) and ITS/5.8S (for fungus) rRNA genes sequences as Pseudomoans aeruginosa and Aspergillus flavus, respectively. Results: The fungal/bacterial consortium exhibited a higher percentage of dyes degradation than the individual strains, even at a high concentration of 300 mg/L. Azoreductase could be identified as the main catabolic enzyme and the consortium could induce azoreductase enzyme in the presence of both dyes. However, the specific substrate which achieved the highest azoreductase specific activity was Methyl red (MR) (3.5 U/mg protein). The tentatively proposed metabolites that were detected by HPLC/MS suggested that the reduction process catalyzed the degradation of dyes. The metabolites produced by the action consortium on two dyes were safe on Vicia faba and Triticum vulgaris germination and health of seedlings. Toxicity of the dyes and their degradation products on the plant was different according to the type and chemistry of these compounds as well as the type of irrigated seeds. Conclusion: We submit that the effective microbial degradation of DB64 and AY17 dyes will lead to safer metabolic products.

Globally fungi have the ecological and biochemical capability to reduce organic and inorganic chemicals and to decrease the risk associated with contaminants, either by chemical alteration or by manipulating chemical bioavailability in wastewater. Moreover, the abundance functional gene seemed to reflect the type of the contamination. With optimized assays, the gene abundances can be used to assess bioremediation efficacy. Since the DNA-based PCR methods are faster than long laboratory incubation for mineralization assays, they provide an additional efficient tool in the monitoring of bioremediation efficiency.

The use of bacteria is a good method for biodegradation of polycyclic aromatic hydrocarbons due to their fast-growing and cost effectiveness. Bacteria can completely mineralize such toxic compounds to harmless by-products. ASU-035 is a bacterial strain, which was isolated from oil contaminated soil. It was identified as Achromobacter denitrificans on the basis of the nucleotide sequence of 16S rRNA gene, and deposited in GenBank under accession number KC342253. Achromobacter denitrificans have been tested for utilization of pyrene as a sole source of carbon and energy. Some pyrene degradative enzymes and ability of this strain for biosurfactants production have been studied. The results illustrated that the strain could utilize 76.5 mg/L of pyrene (100 mg/L) within 18 days with growth rate and mean generation time 0.033 h−1 and 30.3 h, respectively. The maximum specific activities (U/mg protein) of pyrene dioxygenase, catechol 1,2 dioxygenase (C12O), and catechol 2,3 dioxygenase (C23O) were 0.78 ± 0.12, 0.41 ± 0.05, and 0.2 ± 0.01, respectively. Achromobacter denitrificans could enhance the bioavailability of pyrene to get use of it as a sole carbon source by increasing the emulsification activity to 11.5 ± 2.1 U/mg proteins and cell-surface hydrophobicity to 39 ± 1.3 %.

The huge applications of cellulosic and lignocellulosic materials in the various fields of life lead to accumulation of its wastes that became one of the major sources of environmental pollution. In this study, a Gram-positive cellulose-decomposing endophytic bacterium (Chi-04) was isolated from medicinal plant Chiliadenus montanus which inhabitant Saint Catherine (Sinai) region in Egypt. The bacterial strain was identified based on the sequence analysis of 16S rRNA genes as Lysinibacillus xylanilyticus. This isolate was capable of degrading 58% of cellulosic filter paper (100 g/l) within 15 days of incubation. The soluble and reduced sugars were spectrophotometrically determined as cellulose decomposition metabolites. The bacterial isolate exhibited an obvious activity toward cellulase enzyme production. The maximum cellulase activity (0.18 U/min) was detected after 12 days of incubation while the maximum release of soluble sugars (11.85 mg/ml) was detected after 15 days of incubation. CaCl2 nanoparticles (100 nm) were chemically prepared to enhance the activity of the enzyme. The optimum concentration of CaCl2 nanoparticles that showed the highest activity of cellulase (0.3 mg/ml reduced sugar) was 0.6%. The bacterial isolates showed potential convert of cellulose into reducing sugars which could be used in several applications.

Hematite/graphene oxide (FGO) nanocomposites were used as a supporting surface for the fungus Aspergillus terreus AUMC-050 to form AFGO biofilm. Different techniques were used for characterization of nanocomposites and biofilm such as IR, Fourier transform infrared, Scanning electron microscopy, Transmittance Electron Microscopic, Brunauer–Emmett–Teller surface area, and Raman Spectroscopy. The effect of initial dye concentration (0–300 mg/L), contact time (0–80 min), pH values (2.0–8.0), and temperature (10–50°C) was studied. The maximum adsorption capacity of dye using AFGO biofilm was 160 mg dye/g at pH 2.0, and the contact time was 50 min. The best fitted equilibrium and kinetic model were found to be Langmuir and pseudo-first order, respectively. Various thermodynamic parameters were evaluated to determine the nature of biosorption process. The negative value of ΔG and ΔH° indicated spontaneity and exothermic behavior of the adsorption process. Using of microbial biofilm supported on nanocomp...

Presence of synthetic dyes in water bodies, even at very low concentrations can be highly toxic to living organisms, reducing the growth of different microorganisms and preventing the photosynthesis in aqueous flora. Pseudomonas pseudoalcaligenes and biofilm supported on activated carbon were used for adsorption of acid blue 25 (AB 25). The effect of initial dye concentration (0-300 mg/L), contact time (0- 240 min), and pH values (3.0- 8.0) were studied. The optimum pH value for biosorption of AB 25 was pH 3.0 for the two biosorbents, while contact time was180 min for P. pseudoalcaligenes cells and 210 min for the biofilm. The biosorption isotherm study revealed that both Langmuir and Freundlich models were suitable for biosorption process. The maximum adsorption capacities for AB 25 by P. pseudoalcaligenes and biofilm were 98 and 113.4 (mg/g), respectively. On the other hand, the pseudo-second order was a good model for description the biosorption kinetics. Fourier Transform Infrared FT-IR spectrum analysis showed that the presence of amines plays an important role in biosorption process. According to experimental data, the presence of P. pseudoalcaligenes could be enhanced the capacity of activated carbon to adsorb the dye from aqueous solutions.

Polycyclic aromatic hydrocarbons (PAHs) are xenobiotic compounds, which being degraded by chemical, physical or biological methods. The latter is the safest and the cheapest one. Two bacterial strains ASU-01 and ASU-016 were isolated from different Egyptian petroleum contaminated sites. They were genetically identified based on the analysis of the nucleotide sequences of the 16S ribosomal PNA gene and the phylogenetic tree as Enterobacter hormaechei and Pseudomonas pseudoalcaligenes respectively. When pyrene as high molecular weight (HMW)-PAH was added as a sole carbon source, both strains could degrade it with efficiency 77.7 and 83.7% within 15 days of incubation, respectively. However, when it was mixed with low molecular weight (LMW)-PAHs, two opposite phenomena appeared. The first one was enhancement, which occurred with ASU-01. This strain shifted pyrene efficiency to 98.5%. The second phenomenon was inhibition occurred with ASU-016 which completely retarded pyrene degradation. Naphthalene dioxygenase (nahAc), and catechol dioxygenases (C12O and C23O) genes were detected in the two strains based on PCR. The detected genes were confirmed by determining the different specific activities of their translated protein (enzymes) on different PAHs. The maximum values of biosurfacatant production activity and cell-surface and percentage of cell-surface hydrophobicity (CSH) were detected during the exponential phase. These latter factors increased the bioavailability and consequently, the assimilation of PAHs.

Polycyclic aromatic hydrocarbons (PAHs) are serious pollutants and health hazards. In this study, 15 PAHs-degrading bacteria were isolated from Egyptian oily soil. Among them, one Gram-negative strain (ASU-06) was selected and biodegradation ability and initial catabolic genes of petroleum compounds were investigated. Comparison of 16S rRNA gene sequence of strain ASU-06 to published sequences in GenBank database as well as phylogenetic analysis identified ASU-06 asSphingomonas koreensis. Strain ASU-06 degraded 100, 99, 98, and 92.7% of 100 mg/L naphthalene, phenanthrene, anthracene, and pyrene within 15 days, respectively. When these PAHs present in a mixed form, the enhancement phenomenon appeared, particularly in the degradation of pyrene, whereas the degradation rate was 98.6% within the period. This is the first report showing the degradation of different PAHs by this species. PCR experiments with specific primers for catabolic genesalkB, alkB1, nahAc, C12O, andC23Osuggested that ASU-06 might possess genes for aliphatic and PAHs degradation, whilePAH-RHDαGPgene was not detected. Production of biosurfactants and increasing cell-surface hydrophobicity were investigated. GC/MS analysis of intermediate metabolites of studied PAHs concluded that this strain utilized these compounds via two main pathways, and phthalate was the major constant product that appeared in each day of the degradation period.

Waste effluents from textile industries, newspaper printing and photography contain residues of dyes and chemicals. Synthetic dyes present in water bodies, even at very low concentrations, can be extremely toxic to the living organisms due to cutting the development of bacteria and preventing the photosynthesis in aqueous flora. Acid Blue 25 (AB25) and Pigment Yellow 101 (PY101) are two types of azodyes which are toxic organic pollutants that consist of both N=N and C=C chromophoric groups. They cause considerable health effects being irritating to skin, eye and respiratory system and in some cases they may cause cancers. In this study, a biofilm of Aspergillus terreus supported on activated carbon was used as a biological tool for removal of these dyes from water body. The adsorption kinetics and contact time were determined along 240 minutes (30 minute interval). The initial concentration of dyes was 100 mg/L for each one. The biomass dosage was 1g / L. The optimum pH value for adsorption process was 3.0. The results depicted that the contact time for biosorption of both dyes was 180 min while adsorption kinetics of was quietly fitted with Pseudo second-order kinetics equation models. The maximum adsorption capacity was 82.3 and 78.2 mg/g for AB 25 and PY 101, respectively. Freundlich model was a good model for adsorption isotherm of two dyes on biofilm.