Evaluation of the Potential of Cannabis sativa L. (Industrial Hemp) as a Substrate for Biorefinery

Abstract

The growing human population and fossil fuel consumption are causing energy resource depletion and a health crisis, with drug resistance being a major threat. Sustainable development is crucial in these rapidly changing times. The use of biorefineries is one of the key tactics for reaching sustainable goals. These establishments concentrate on generating bioenergy and other value-added products from renewable biological resources such as biomass. In the current study Cannabis sativa also known as industrial hemp was used for biorefinery purpose. The oil from the seeds was used to generate biodiesel, while extracts from the plant’s seed cake, was used to check its potential in medications with antibacterial qualities. Phytochemical screening of C. sativa seed oil and de-oiled seed cake extracts was carried out using qualitative phytochemical analyses. Its phytochemical properties are due to a variety of beneficial substances, including flavonoids, saponins, steroids/terpenes, resins/balsams, alkaloids, glycosides, tannins, and phenols, which were all detected in it. The antifungal potential of extracts of Cannabis sativa pressed seed cake and seed oil were examined against five selected strains: Candida albicans, Aspergillus flavus, Aspergillus niger, Fusarium oxysporum and Curvularia lunata.. All fungal strains wee susceptible to the extracts. N-Hexane showed the highest antifungal activity. Mic assay carried out on microtiter plates. Show thatmst of the MIC concentrations were in range of 3-0.3 mg/mL and for synergistic assay 0.03 mg/mL of combined extract and Nilstat is required to kill 80% of the microbes. The bacterial strains were Gram-negative, Multi Drug Resistant, MDR, human pathogens (Pseudomonas aeruginosa, Klebsiella pneumonia, Salmonella) strains were used. All extracts were positive for antibacterial activity, but the antibacterial drug used Tetracycline showed the minimum activity indicating these strains are somewhat resistant to this drug. Oil also exhibited minimum activity. Methanolic extracts were most efficient against MDR strains. The tetracycline combined with extracts gave antagonistic effect. MIC assay indicated that extracts minimum inhibitory concentration was 30mg/mL, whereas the combined assay showed these extracts and drug has antagonistic effect. Pathogenic extracts showed little to moderate activity against extracts and oil . in synergistic assay when combined with Nilstat they gave additive effect. xi Among the extracts methanolic extract showed activity in all strains. DPPH assay indicated the highest antioxidant potential is exhibited by oil, 71% whereas methanol showed least antioxidant potential of 38%. Brine shrimp assay carried out to determine cytotoxic effect indicates only methanolic and n-hexane extract s showed cytotoxic effect. Chemical transesterification was used to evaluate the viability of producing biodiesel from the oil from Eruca sativa seeds. At standard reaction conditions yield obtained was 60% The results showed that the acid value, free fatty acid content, saponification value, ester value, and % glycerin was, 1.33, 0.746, 194.12, 192.79, and 10.53 respectively. After optimization of parameters, the highest volumetric yield of biodiesel 84% was recorded with conditions: temperature 50 degrees, oil to methanol ratio 1:9, catalyst concentration 1%, RPM 600 and reaction time 90 minutes. The whole cell approach, with oil: methanol, 37°C temperature, n-hexane solvent, 48-hour time, yielded 63% biodiesel. Hence, the results of the current study demonstrate that the Cannabis sativa plant is an excellent feedstock for biorefineries.