Egypt faces a high population growth rate nowadays, which demands for an increase in agricultural production efficiency. Consequently, agricultural field residues will increase. Rice straw is one of the main agriculture residues in Egypt. So this study was performed on rice straw as a resource for production of bioethanol. Eight microbial isolates, five yeasts and three fungi were isolated from rice straw. Yeast isolates were selected for their ability to utilize different sugars and cellulose. Chipped and grinded rice straw was subjected to different pretreatment methods physically through steam treatment by autoclaving and different doses of gamma γ irradiation (50 and 70 Mrad). Autoclaved pretreated rice straw was further enzymatically treated throughout solid state fermentation process by different fungal isolates; F68, F94 and F98 producing maximum total reducing sugars of 12.62, 13.58, 17.00 g/L, respectively. Bioethanol production by separate microbial hydrolysis and fermentation (SHF) process of rice straw hydrolysate was performed by the two selected fungal isolates; Trichoderma viride F94 and Aspergillus terreus F98 and two yeast isolates (Y26 and Y39). The two yeast isolates have been identified by 18S, RNA as Candida tropicalis Y26 and Saccharomyces cerevisiae Y39. SHF processes by F94 and Y26 produced 45 gallon/ton rice straw while that of F98 and Y39 produced 50 gallon/ton rice straw.

The usage of marine macroalgae (i.e. seaweeds) as feedstock for bioethanol; an alternative and/or complimentary to petro-fuel, would act as triple fact solution; bioremediation process for ecosystem, renewable energy source and economy savings.

Three halotolerant bacterial species were isolated from locally oil-polluted water sample for their ability to utilize asphaltene (Asph) fraction as sole carbon and energy source. These bacteria degrade 83–96% of 2500 mg/L asphaltene within 21 d at30°Cand pH7. They were identified asBacillussp. Asph1,Pseudomonas aeruginosaAsph2, andMicrococcussp. Asph3. A statistically significant difference at 95% confidence level for cell growth and percentage biodegradation (%BD) was observed in all biotreatment flasks relative to noninoculated (–ve control) flasks. Regression analysis estimated a quadratic polynomial equation for Asph biodegradation as a function of cell growth. Gel permeation chromatographic (GPC) and Fourier transform infrared (FT-IR) analysis revealed decrease in Asph average molecular weights and significant alternations in functional groups after biotreatment, respectively.

This research provides a helpful insight into the development of a new mycosynthesized antimicrobial agent.

This study provides a new emphasis for research on the valorization of biowastes into nanocatalyst and biorefineries to be integrated with petroleum bioupgrading and polluted water treatment. The response surface optimized batch transesterification of waste‐frying oil using methanol and sustainable animal bone valorized fluorapatite nanocatalyst (FAP) yielded approximately 97% biodiesel via a pseudo‐second‐order reaction with an efficient rate of 0.48 (mol L−1)−1min−1 and activation energy of 13.11 kJ mol−1. In a pioneering step, by‐products of the starch industry and the biodiesel transesterification process; corn‐steep liquor (CSL 0.2 g L−1) and bioglycerol (6.24 g L−1) as nitrogen and carbon sources, increased the dibenzothiophene biodesulfurization (BDS) efficiency of a novel biodesulfurizing Rhodococcus jialingiae strain HN3 (NCBI Gene Bank Accession No. MN173539) sixfold. Further, upon the application of such bioproducts in a batch BDS process (1/3 petro‐diesel/water) of 96 h; HN3 desulfurized 82.26% of 0.62 wt.% sulfur without affecting the petro‐diesel calorific value. In an attempt to reach zero waste, an auxiliary pioneering step was performed, where the spent waste FAP, after being efficiently used for four successive transesterification cycles, was applied to photo‐remediate 4‐nitrophenol polluted water under UV‐irradiation. Advantageously, the fresh and spent waste FAP recorded the same photodegradation capabilities. Where they obeyed the Langmuir–Hinshelwood kinetic model (R2 ≥ 0.966) recording the same rate constants (kapp 0.032 min−1) and were efficiently reused for four successive polluted‐water treatment cycles. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd