Browsing by Author "Alghamdi, Azzah I."

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Application and characterization of crude fungal lipases used to degrade fat and oil wastes
(2021) Alabdalall, Amira Hassan; Amira Alabdalall; Azzah Ibrahim Alghamdi; Amer, Fatma H. I.; Aldakheel, Fatimah A.; Fatma Hamza Ibrahim Amer; Alghamdi, Azzah I.; Al-Khaldi, Eida M.
Aspergillus niger MH078571.1 and A. niger MH079049.1 were identified previously as the two highest Aspergillus niger strains producing lipase. Biochemical characterizations of lipase activity and stability for these two strains were examined and revealed that the optimal temperature is 45 °C at pH 8for A. niger MH078571.1 and 55 °C for MH079049.1. The lipase production of both strains was studied on medium contains waste oil, as a cheap source to reduce the industrial cost, showed that the optimal incubation period for the enzyme production is 3 days. Moreover, an experiment on lipase activates in organic solvents demonstrated that 50% of acetone is the best solvent for the two strains. In the presence of surfactants, 0.1% of tween 80 surfactant showed the best lipase activities. Furthermore, Mg2+ and Zn2+ ions enhanced the lipase activity of A. niger MH078571.1, while Na2+ and Cu2+ enhanced the enzyme activity of A. niger MH079049.1. Lipase activity was also tested for industrial applications such as integrating it with different detergents. Maximum lipase activity was obtained with 1% of Omo as a powder detergent for both strains. In liquid detergent, 0.1% of Fairy showed maximum lipase activity in A. niger MH078571.1, while the lipase in A. niger MH079049.1 was more effective in 1% of Lux. Moreover, the degradation of natural animal fat with crude enzyme was tested using chicken and sheep fats. The results showed that more than 90% of fats degraded after 5 days of the incubation period.
Isolation, Screening, and Identification of Alkaline Protease-Producing Bacteria and Application of the Most Potent Enzyme from Bacillus sp. Mar64
(2023) Kotb, Essam; Essam Kotb; Alsayed, Mariam A.; Azzah Ibrahim Alghamdi; Alkhaldi, Eida; AbdulAzeez, Sayed; Sayed Abdul Azeez
In this study, thirty-seven alkaline protease-producing bacteria were recovered from different regions of Saudi Arabia. The proteolytic strain with the highest productivity was identified as Bacillus sp. Mar64. Maximum productivity of Mar64P alkaline protease was reached at 60 h, pH 9.0, and 45 °C using 1% tyrosine and 0.5% maltose as nitrogen and carbon supplies, respectively. Specific activity was intensified to 8.5-fold with a recovery of 12.4% and SDS—PAGE revealed one band at 28 kDa after enzyme purification. Mar64P was maximally active at 55 °C and pH 11.0 with thermal stability up to 70 °C and pH stability at 7.0–12.0 for 1 h. It was inhibited by EDTA and unaffected by PMSF, therefore tentatively classified as metalloprotease-type. Storage efficacy was effective for up to eight weeks and it was durable in presence of organic solvents (20%, v/v) such as acetonitrile, acetone, and isopropanol upto to 15 days. The enzyme was compatible with dry detergents at both low and high temperature, in addition, was successful in removing various stains such as blood, egg yolk, chocolate, tea, coffee, and sweat. Furthermore, it was successful in removing skin hairs and hydrolyzing gelatin of waste X-ray films. Collectively, due to these unique properties, Mar64P could be considered an environmentally friendly candidate in both detergent and leather industries.
Microwave-Assisted Synthesis of Phthalazinone Derivatives with Biological Activity and In Silico Antiproliferative Studies
(2022) Rasha Almalih; Abubshait, Haya A.; Almalih, Rasha; Mohamed Sayed Mansour; Nawaz, Muhammad; Azzah Alghamdi; Alghamdi, Azzah I.
Abstract Several nitrogen heterocycles are considered as privileged scaffolds in drug discovery and are present in several drugs with diverse biological activities. Herein, we report the synthesis and characterization of phthalazinone derivatives by using a green synthesis protocol under microwave irradiation. The reduced reaction time and high yield are some of the advantages that render this procedure a greener alternative to conventional chemical synthesis. The structures of all new derivatives were confirmed by spectral analysis. Synthesized derivatives show an effective antimicrobial effect. These compounds were also screened for their in vitro anticancer activity against colon cancer cell line (HCT116). Among the synthesized derivatives are exhibited the highest anticancer activity with IC50 of 28.97±0.11, 66.25±0.14 and 76.04±0.09 μM respectively. The antiproliferative activity was supported by molecular docking studies that showed that phthalazinone derivatives would potentially act through inhibition of PARP. The simulation studies substantiated the biological results as an active compounds in term of binding interactions and scores.
Screening for chitin degrading bacteria in the environment of Saudi Arabia and characterization of the most potent chitinase from Streptomyces variabilis Am1
(2023) Batool M. AlGarudi; Alabdalall, Amira H.; Safa K. AlZuwaid; Amira Alabdalall; Aldakeel, Sumayh A.; Essam Kotb; Ibtisam Mohammed Ababutain; Algarudi, Sakina M.; Ahmed, Asmaa A.; Albarrag, Ahmed M.
Forty-six promising chitinolytic isolates were recovered during a screening for chitinolytic bacteria in the environment of Saudi Arabia. The top three isolates belonged to the genus Streptomyces. Streptomyces variabilis Am1 was able to excrete the highest amount of chitinases, reaching the maximum at 84 h with 0.5% yeast extract and nitrogen source and 2% galactose as a carbon source. Purification of chitinase by DEAE-Cellulose and Sephadex G75 improved the specific activity to 18.6-fold and the recovery to 23.8% and showed a mass at 56 kDa. The optimal catalysis of the purified chitinase was at 40 °C and pH 8 with high thermostability and pH stability as reflected by a midpoint temperature value of 66.6 °C and stability at pH 4–9. The protein reagents SDS, EDTA, and EGTA significantly inhibited the enzyme and the EDTA-chelated chitinase restored its activity after the addition of Fe2+ ions suggesting a metallo-chitinase type with ferric ions as cofactors. Chitinase exerted high antifungal activity against some phytopathogenic fungi. Interestingly, the tested Streptomyces were able to produce chitosan nanocubes along with chitosan from chitin degradation which may be an additional power in their antifungal activity in nature. This work also reveals the importance of unexplored environments as a pool of promising microorganisms with biotechnological applications.