Hamed Hamouda
@qibebt.cas.cn
Qingdao Institute of Bioenergy and Bioprocess technology
Scopus Publications
Scopus Publications
Yimiao Chen, Fangfang Ci, Hong Jiang, Di Meng, Hamed I. Hamouda, Chunhui Liu, Yongyi Quan, Suxue Chen, Xinxue Bai, Zhaohui Zhang,et al.
Elsevier BV
Samah Shabana, Hamed I. Hamouda, Alkassoumi Hassane Hamadou, Busati Ahmed, Zhe Chi, and Chenguang Liu
Elsevier BV
Hamed I. Hamouda, Mohamed S. Selim, Shimaa A. Higazy, Samah Shabana, Zhifeng Hao, and Chenguang Liu
Elsevier BV
Lili Wang, Hamed I. Hamouda, Yueyang Dong, Hong Jiang, Yongyi Quan, Yimiao Chen, Yan Liu, Jiaqi Wang, Mohamed A. Balah, and Xiangzhao Mao
Elsevier BV
Hamed I. Hamouda, Yi-Xuan Fan, Mohnad Abdalla, Hang Su, Ming Lu, and Fu-Li Li
Springer Science and Business Media LLC
Hekmat R. Madian, Hamed I. Hamouda, and Mohamed Hosny
Elsevier BV
Samah Shabana, Hamed I. Hamouda, Mohnad Abdalla, Mohamed Sharaf, Zhe Chi, and Chenguang Liu
Elsevier BV
Zewei Lu, Hong Jiang, Hamed I. Hamouda, Tao Wang, Yueyang Dong, and Xiangzhao Mao
American Chemical Society (ACS)
λ-Carrageenase with high activity is an effective and environmentally friendly tool enzyme for the preparation of λ-carrageenan oligosaccharides with various biological activities. Herein, a novel GH150 (glycoside hydrolases family 150) λ-carrageenase OUC-CglA from Maribacter vaceletii was heterologously expressed, purified, and characterized. The recombinant OUC-CglA performs strict selectivity toward λ-carrageenan with a specific activity of 418.7 U/mg under its optimal reaction conditions of 20 °C and pH 7.0. Additionally, OUC-CglA is a typical cold-adapted λ-carrageenase because it unfolds 90% and 63% of its maximum activity at 15 and 10 °C, respectively. The hydrolysis process suggests that OUC-CglA is an endotype λ-carrageenase with the final products consisting of λ-neocarrabiose, λ-neocarratetraose, λ-neocarrahexaose, and other long-chain λ-neocarrageenan oligosaccharides. As a result, high activity, cold-adaptation, and principal products of OUC-CglA make it a potential biocatalyst for the effective preparation of λ-carrageenan oligosaccharides.
Mohamed Sharaf, Alaa H. Sewid, H. I. Hamouda, Mohamed G. Elharrif, Azza S. El-Demerdash, Afaf Alharthi, Nada Hashim, Anas Abdullah Hamad, Samy Selim, Dalal Hussien M. Alkhalifah,et al.
American Society for Microbiology
Antimicrobial resistance poses a great threat and challenge to humanity. Therefore, the search for alternative ways to target and eliminate microbes from plant, animal, and marine microorganisms is one of the world’s concerns today.
Mohamed Mohsen, Chenggang Lin, Hamed I. Hamouda, Ahmed M. Al-Zayat, and Hongsheng Yang
Frontiers Media SA
Microorganisms colonize plastics in the aquatic environment but their composition on plastics used in aquaculture remains poorly studied. Microorganisms play a significant role in aquaculture in terms of water quality and the health of cultivated species. In the current study, we explored the composition of microorganisms on floating plastics and their surrounding water collected from ponds and open aquaculture areas. Using scanning electron microscopy, the diversity of microbial communities, primarily diatoms, and bacteria were identified on the plastic surfaces. Additionally, epifluorescence microscopy revealed that prokaryotes were colonized on all plastic samples from 0.1 to 29.27×103 cells/cm2, with a high abundance found in open aquaculture areas compared to ponds. Bacterial communities were characterized by 16S rRNA sequencing which showed that bacterial communities on plastics were dominated by Proteobacteria, Cyanobacteria, Bacteroidetes, and Actinobacteria. The level of these microbial communities on the plastics differed from those found in the surrounding seawater samples and the abundance of potentially pathogenic bacteria was higher in plastics than in seawater samples. Moreover, hydrocarbon-degrading bacteria were more abundant in the investigated plastic samples than in the water samples. This study contributes to the knowledge regarding the plastisphere community in aquaculture.
Yanjun Qiu, Hong Jiang, Yueyang Dong, Yongzhen Wang, Hamed I. Hamouda, Mohamed A. Balah, and Xiangzhao Mao
MDPI AG
Fucoidan is one of the main polysaccharides of brown algae and echinoderm, which has nutritional and pharmacological functions. Due to the low molecular weight and exposure of more sulfate groups, oligo-fucoidan or fucoidan oligosaccharides have potential for broader applications. In this research, a novel endo-α-1,4-L-fucoidanase OUC-FaFcn1 which can degrade fucoidan into oligo-fucoidan was discovered from the fucoidan-digesting strain Flavobacterium algicola 12,076. OUC-FaFcn1 belongs to glycoside hydrolases (GH) family 107 and shows highest activity at 40 °C and pH 9.0. It can degrade the α-1,4 glycosidic bond, instead of α-1,3 glycosidic bond, of the fucoidan with a random tangent way to generate the principal product of disaccharide, which accounts for 49.4% of the total products. Therefore, OUC-FaFcn1 is a promising bio-catalyst for the preparation of fucoidan-derived disaccharide. These results further enrich the resource library of fucoidanase and provide the basis for the directional preparation of fucoidan-derived oligosaccharide with specific polymerization.
Lili Wang, Hong Jiang, Yanjun Qiu, Yueyang Dong, Hamed I. Hamouda, Mohamed A. Balah, and Xiangzhao Mao
American Chemical Society (ACS)
Myrosinase is a biotechnological tool for the preparation of sulforaphane and sulforaphene with a variety of excellent biological activities. In this study, a gene encoding the novel glycoside hydrolase family 3 (GH3) myrosinase Rmyr from Rahnella inusitata was heterologously expressed in Escherichia coli BL21 (DE3). The purified Rmyr shows the highest activity at 40 °C and pH 7.0; meanwhile, its half-life at 30 °C reaches 12 days, indicating its excellent stability. Its sinigrin-, glucoraphenin-, and glucoraphanin-hydrolyzing activities were 12.73, 4.81, and 6.99 U/mg, respectively. Rmyr could efficiently degrade the radish seed-derived glucoraphenin and the broccoli seed-derived glucoraphanin into sulforaphene and sulforaphane within 10 min with the highest yields of 5.07 mg/g radish seeds and 9.56 mg/g broccoli seeds, respectively. The highest conversion efficiencies of sulforaphane from glucoraphanin and sulforaphene from glucoraphenin reached up to 92.48 and 97.84%, respectively. Therefore, Rmyr is a promising and potent biocatalyst for efficient and large-scale preparation of sulforaphane and sulforaphene.
Mohamed Sharaf, Muhammad Arif, Hamed I. Hamouda, Sohaib Khan, Mohnad Abdalla, Samah Shabana, Hussein. E. Rozan, Tehsin Ullah Khan, Zhe Chi, and Chenguang Liu
Elsevier BV
Mohamed Sharaf, H.I. Hamouda, Samah Shabana, Sohaib Khan, Muhammad Arif, Hussein. E. Rozan, Mohnad Abdalla, Zhe Chi, and Chenguang Liu
Elsevier BV
H.I. Hamouda, H.M. Abdel-Ghafar, and M.H.H. Mahmoud
Elsevier BV
Nasir Ali, Hamed I. Hamouda, Hang Su, Jie Feng, Zi-Yong Liu, Ming Lu, and Fu-Li Li
Elsevier BV
Abstract Biological pretreatment is feasible for enhancing methane generation with crop residues. Improvement of the degradation efficiency of cellulose has always been the key to improve methane yield. The role of an anaerobic and thermophilic bacterium, Caldicellulosiruptor sp. F32, on the degradation of corn stalk was investigated. A pure bacterial pretreatment system (0.20 v/v), with 20 times CFU of 2.20 × 108 was verified to be beneficial to the deterioration of corn stalk residues and the increase of methane output. The highest methane yield was 250.2 mL/g volatile solid, which was 28% higher than that from the untreated group. In group 4, the concentrations of glucose and volatile fatty acids were higher than those in other groups. Furthermore, the assays by Fourier-transform infrared spectra and X-ray diffraction revealed that the crystallinity indexes of pretreated groups declined. Hence, biology-based pretreatment using pure bacterial system, Caldicellulosiruptor sp. F32, is a potentially effective approach to improve the degradation efficiency of lignocellulosic biomass.
Hamed I. Hamouda, Nasir Ali, Hang Su, Jie Feng, Ming Lu, and Fu-Li Li
American Society for Microbiology
ABSTRACT Pectin deconstruction is the initial step in breaking the recalcitrance of plant biomass by using selected microorganisms that encode pectinolytic enzymes. Pectate lyases that cleave the α-1,4-galacturonosidic linkage of pectin are widely used in industries such as papermaking and fruit softening. However, there are few reports on pectate lyases with good thermostability. Here, two pectate lyases (CbPL3 and CbPL9) from a hyperthermophilic bacterium, Caldicellulosiruptor bescii, belonging to family 3 and family 9 polysaccharide lyases, respectively, were investigated. The biochemical properties of the two CbPLs were shown to be similar under optimized conditions of 80°C to 85°C and pH 8 to 9. However, the degradation products from pectin and polygalacturonic acids (pGAs) were different. A family 66 carbohydrate-binding module (CbCBM66) located in the N terminus of the two CbPLs shares 100% amino acid identity. A CbCBM66-truncated mutant of CbPL9 showed lower activities than the wild type, whereas CbPL3 with a CbCBM66 knockout portion was reported to have enhanced activities, thereby revealing the different effect of CbCBM66. Prediction by the I-TASSER server revealed that CbCBM66 is structurally close to BsCBM66 from Bacillus subtilis; however, the COFACTOR and COACH programs indicated that the substrate-binding sites between CbCBM66 and BsCBM66 are different. Furthermore, a substrate-binding assay indicated that the catalytic domains in the two CbPLs had strong affinities for pectate-related substrates, but CbCBM66 showed a weak interaction with a number of lignocellulosic carbohydrates. Finally, scanning electron microscopy (SEM) analysis and a total reducing sugar assay showed that the two enzymes could improve the saccharification of switchgrass. The two CbPLs are impressive sources for the degradation of plant biomass. IMPORTANCE Thermophilic proteins could be implemented in diverse industrial applications. We sought to characterize two pectate lyases, CbPL3 and CbPL9, from a thermophilic bacterium, Caldicellulosiruptor bescii. The two enzymes share a high optimum temperature, a low optimum pH, and good thermostability at the evaluated temperature. A family 66 carbohydrate-binding module (CbCBM66) was identified in the two CbPLs, sharing 100% amino acid identity. The deletion of CbCBM66 dramatically decreased the activity of CbPL9 but increased the activity and thermostability of CbPL3, suggesting different roles of CbCBM66 in the two enzymes. Moreover, the degradation products of the two CbPLs were different. These results revealed that these enzymes could represent potential pectate lyases for applications in the paper and textile industries.
Mohamed S. Selim, Hamed Hamouda, Zhifeng Hao, Samah Shabana, and Xiang Chen
Royal Society of Chemistry (RSC)
Three nanorods (NRs) of γ-AlOOH, γ-MnOOH, and α-Mn2O3 were synthesized by controlled regimes and applied as antimicrobial agents. Different microbial strains were used for the assessments and the results approved the highest activity for α-Mn2O3 NRs.
Nasir Ali, Hamed I. Hamouda, Hang Su, Fu-Li Li, and Ming Lu
Elsevier BV
The purpose of this study was to improve methane generation from corn stalk (CS) through alkaline hydrogen peroxide and lithium chloride/N,N-dimethylacetamide (AHP-LiCl/DMAc) pretreatment. Changes in the structures of treated and untreated CSs were investigated, and biomass components, including cellulose, hemicellulose and lignin, were analysed. Our findings revealed that AHP-LiCl/DMAc pretreatment improved accumulative methane yield by forceful delignification and effectively destroyed the structure of cellulose. The AHP-LiCl/DMAc-treated group had a maximum methane yield of 318.6 ± 17.85 mL/g volatile solid, which was 40.08% and 10.10% higher than the maximum methane yields of the untreated and AHP-treated group, respectively. This result showed enhanced cellulose dissolution by the ionic solvent of LiCl/DMAc and improved enzymatic saccharification in fermentative bacteria without structural modifications. The AHP-LiCl/DMAc treated group had higher glucose level, acetate followed by biomethanation process. Furthermore, the decrease in crystallinity indexes for AHP-LiCl/DMAc treated group was reported. Overall, this investigation proved a promising pretreatment approach for enhancing the degradation of CS into reducing sugars and improving methane generation.
Hekmat R. Madian, Nagwa M. Sidkey, Mostafa M. Abo Elsoud, Hamed I. Hamouda, and Ahmed M. Elazzazy
Springer Science and Business Media LLC
Biofuel production has attracted much attention in the last few decades. Much effort has been applied to decrease the production cost of bioethanol by using agricultural waste materials. Saccharification of lignocellulosic agricultural waste materials increases the amount of available sugars and thus reduces bioethanol production costs. Here, about 14 g/l of bioethanol (185 mg/g of dry material) was produced by Candida tropicalis Y-26 using production medium with water hyacinth hydrolysate as the sole carbon source. This hydrolysate was produced, after screening and mathematical modeling, by a combination of Aspergillus terreus F-98 and acid hydrolysis $$(\\hbox {H}_{2}\\hbox {SO}_{4})$$(H2SO4) treatments to give 409 mg/g total reducing sugars. The use of a combination of A. terreus F-98 and acid hydrolysis with $$\\hbox {H}_{2}\\hbox {SO}_{4}$$H2SO4, 4.66% (v/v); water hyacinth biomass, 7.56% (w/v); reaction temperature, $$119.27\\,^{\\circ }\\hbox {C}$$119.27∘C; and reaction time, 16.11 min was optimal for the saccharification of water hyacinth.
Mohnad Abdalla, Wafa Ali Eltayb, Amr Ahmed El-Arabey, Raihan Mo, T. I. M. Dafaalla, Hamed I. Hamouda, Eijaz Ahmed Bhat, Annoor Awadasseid, and Hassan Abdellha Ahmed Ali
Springer Science and Business Media LLC
BackgroundGrx6 is a yeast Golgi/endoplasmic reticulum protein involved in iron-sulfur binding that belongs to monothiol glutaredoxin-protein family. Grx6 has been biochemically characterized previously. Grx6 contains a conserved cysteine residue (Cys-136). Depending on the active-site sequences, Grxs can be classified to classic dithiol Grxs with a CXXC motif known as classes II and monothiol Grxs with a CXXS motif known as classes I, and Grx6 belongs to the class I with a CSYS motif.ResultsOur results showed how the loop between the N-terminal and C-terminal can affect the stability. When Grx6 was incubated with FeSO4·7H2O and (NH4)2Fe(SO4)2·6H2O, a disulfide bond was formed between the cysteine 136 and glutathione, and the concentration of dimer and tetramer was increased. The results presented various levels of stability of Grx6 with mutant and deleted amino acids. We also highlighted the difference between the monomer and dimer forms of the Grx6, in addition to comparison of the Fe-S cluster positions among holo forms of poplar Grx-C1, human Grx2 and Saccharomyces cerevisiae Grx6.ConclusionsIn this paper, we used a combination of spectroscopic and proteomic techniques to analyse the sequence and to determine the affected mutations and deletions in the stability of Grx6. Our results have increased the knowledge about the differences between monomer and dimer structures in cellular processes and proteins whose roles and functions depend on YCA1 in yeast.
H. I. Hamouda, H. N. Nassar, H. R. Madian, Mohamed Helal El-Sayed, A. A. El-Ghamry, and N. Sh. El-Gendy
Informa UK Limited
ABSTRACT In an attempt to produce bioethanol as a renewable and natural energy resource and as a promising alternative/complement to conventional petrol (i.e., gasoline), 44 microbial isolates (12 yeast and 32 bacterial strains) were isolated from molasses samples obtained from some of the sugar factories in Egypt. Among the microbial isolates obtained, only two yeast isolates (HSC-22 and HSC-24) were selected from sugarcane molasses (SCM) for their high bioethanol fermentation capabilities, recording bioethanol production of ≈9.6 and 8.2 g/L with actual yield of 0.48 and 0.41 g ethanol/g SCM, respectively, within 48-h incubation period at 30°C. Phylogenetic identification of these isolates was performed based on the analysis of the nucleotide sequence of the 18S rDNA gene, which indicated that these isolates can be identified as Pichia veronae and Candida tropicalis, respectively, with similarity of 99%.