The effect of fermentation by Bacillus subtilis and Aspergillus niger on the nutritional value of date palm kernels

Document Type : Original Research Articles (Regular Papers)


1 Department of Animal Science, College of Agriculture and Natural Resources, University of Gonbad Kavous, Gonbad Kavous, Iran

2 Agriculture Department, Payame Noor University

3 Department of Animal Science, Faculty of Agriculture, Gonbad Kavous University, Gonbad, Iran

4 Department of Animal Science, Faculty of Agriculture and Natural Resources, Gonbad Kavous University, Iran



This study was performed to investigate the effect of fermentation by Bacillus subtilis (B. subtilis) and Aspergillus niger (A. niger) and alkaline processing on the nutritional value and chemical composition of date palm kernels (DPK). DPK was fermented for 28 days under solid-state fermentation culture with two different microorganisms (B. subtilis and, or A. niger). Alkaline processing was performed by soaking DPK in NaOH solution for 24 hours. In this experiment, eight treatments were used: DPK (control), DPK fermented by B. subtilis, and A. niger separately or in combination, and processed with NaOH, alone or with B. subtilis or A. niger or both. Digestibility and gas production of fermented and processed DPK were performed using the batch culture and gas production techniques. The results showed that there was an increase in crude protein (CP) and a decrease in crude fiber concentrations due to the fermentation of DPK with B. subtilis and A. niger (P < 0.05). Total phenol content in fermented DPK (FDPK) with B. subtilis and A. niger was significantly lower than the control. Gas production significantly increased in FDPK compared to control and NaOH-treated samples (p <0.05). All treatments significantly increased the in vitro digestibility of DM (IVDOD) and OM (IVOMD) compared to the control (p < 0.01). Among the treatments, simultaneous fermentation of DPK with B. subtilis and A. niger had the most significant effect on increasing the microbial CP (MCP) and its efficiency (EMCP; p <0.01).


Main Subjects


Abdeshahian P., Samat N., Hamid A.A., Yusoff W.M.W., 2010. Utilization of palm kernel cake for production of β-mannanase by Aspergillus niger FTCC 5003 in solid substrate fermentation using an aerated column bioreactor. Journal of Industrial Microbiology & Biotechnology 37, 103-109.
 Abid K., Jabri J., Beckers Y., Yaich H., Malek A., et al. 2019. Influence of adding fibrolytic enzymes on the ruminal fermentation of date palm by-products. Archives Animal Breeding 62, 1-8.
 Aboragah A., Embaby M., Günal M., AbuGhazaleh A., 2019. Effect of alkaline and sonication pretreatments on the rumen degradability of date palm seeds. Tropical Animal Health and Production 52, 771-776.
 Ademark P., Varga A., Medve J., Harjunpää V., Drakenberg T. et al. 1998. Softwood hemicellulose-degrading enzymes from Aspergillus niger: purification and properties of a β-mannanase. Journal of Biotechnology 63, 199-210.
 Afiq M.A., Rahman R.A., Man Y.C., Al-Kahtani H., Mansor T., 2013. Date seed and date seed oil. International Food Research Journal 20, 2035-2043.
 Al-Farsi M.A., Lee C.Y., 2008. Nutritional and functional properties of dates: a review. Critical Reviews in Food Science and Nutrition 48, 877-887.
 AOAC., 2005. Official Methods of Analysis. Vol. 1. No. 1. 18th ed. Association of Official Analytical Chemists. Washing Town, D.C.
 Araujo A., Ward O.P., 1990. Extracellular mannanases and galactanases from selected fungi. Journal of Industrial Microbiology 6, 171-178.
Asgari G., Chavoshani A., Seid-Mohammadi A., Rahmani A., 2013. Removal of pentachlorophenol using microwave assisted persulfate from synthetic wastewater. Journal of Water and Wastewater 25-33.
Ashayerizadeh A., Dastar B., Shargh M.S., Mahoonak A.S., Zerehdaran S., 2017. Fermented rapeseed meal is effective in controlling Salmonella enterica serovar Typhimurium infection and improving growth performance in broiler chicks. Veterinary Microbiology 201, 93-102.
ASIA I. 2013. Food and Agriculture Organization of the United Nations. Rome.
Aziz H., 2020. Utilization of date palm leaves treated with enzymes in small ruminants feeding. Egyptian Journal of Nutrition and Feeds 23, 55-70.
 Behera S., Arora R., Nandhagopal N., Kumar S., 2014. Importance of chemical pretreatment for bioconversion of lignocellulosic biomass. Renewable and Sustainable Energy Reviews 36, 91-106.
 Blümmel M., Steingaβ H., Becker K., 1997. The relationship between in vitro gas production, in vitro microbial biomass yield, and 15 N incorporation and its implications for the prediction of voluntary feed intake of roughages. British Journal of Nutrition 77, 911-921.
 Broderick G., Kang J., 1980. Automated simultaneous determination of ammonia and total amino acids in ruminal fluid and in vitro media1. Journal of Dairy Science 63, 64-75.
 Carlile M.J., Watkinson S.C., Gooday G.W., 2001. The fungi. Gulf Professional Publishing
 Chandrasekaran M., Bahkali A.H., 2013. Valorization of date palm (Phoenix dactylifera) fruit processing by-products and wastes using bioprocess technology–Review. Saudi Journal of Biological Sciences 20, 105-120.
 Chuan C.H., Krishnaiah K., Wong C.M., Janaun J.Palm kernel cake as substrate for βmannanase production by Bacillus subtilis ATCC3366 under submerged and solid state fermentations. Proc. Proceedings of the 1st International Conference on Natural Resources Engineering & Technology. 2006.
 Crueger W., Crueger A., Brock T.D., Brock T.D., 1990. Biotechnology: a Textbook of Industrial Microbiology.
 Dei H., Rose S., Mackenzie A., Amarowicz R., 2008. Growth performance of broiler chickens fed diets containing shea nut (Vitellaria paradoxa, Gaertn.) meal fermented with Aspergillus niger. Poultry Science 87, 1773-1778.
Dusterhoft E.M., Posthumus M., Voragen A., 1992. Non‐starch polysaccharides from sunflower (Helianthus annuus) meal and palm‐kernel (Elaeis guineensis) meal—investigation of the structure of major polysaccharides. Journal of the Science of Food and Agriculture 59, 151-160.
 Falony G., Armas J.C., Mendoza J.C.D., Hernández J.L.M., 2006. Production of Extracellular Lipase from Aspergillus niger by Solid-State Fermentation. Food Technology & Biotechnology 44, 235-240.
 Gao J., Weng H., Zhu D., Yuan M., Guan F. et al. 2008. Production and characterization of cellulolytic enzymes from the thermoacidophilic fungal Aspergillus terreus M11 under solid-state cultivation of corn stover. Bioresource Technology 99, 7623-7629.
 Getachew G., DePeters E., Robinson P., 2004. In vitro gas production provides effective method for assessing ruminant feeds. California Agriculture 58, 54-58.
 Ghehsareh A.M., Samadi N., Borji H., 2011. Comparison of date-palm wastes and perlite as growth substrates on some tomato growing indexes. African Journal of Biotechnology 10, 4871-4878.
 Guo J., Dong X., Liu S., Tong J., 2017. Effects of long-term Bacillus subtilis CGMCC 1.921 supplementation on performance, egg quality, and fecal and cecal microbiota of laying hens. Poultry Science 96, 1280-1289.
 Hassain M.Z., Abe J.-i., Hizukuri S., 1996. Multiple forms of β-mannanase from Bacillus sp. KK01. Enzyme and Microbial Technology 18, 95-98.
 Iluyemi F., Hanafi M., Radziah O., Kamarudin M., 2006. Fungal solid state culture of palm kernel cake. Bioresource Technology 97, 477-482.
 Jackson M., 1977. The alkali treatment of straws. Animal Feed Science and Technology 2, 105-130.
Jazi V., Boldaji F., Dastar B., Hashemi S., Ashayerizadeh A., 2017. Effects of fermented cottonseed meal on the growth performance, gastrointestinal microflora population, and small intestinal morphology in broiler chickens. British Poultry Science 58, 402-408.
 Jeguirim M., Dorge S., Trouvé G., Said R., 2012. Study on the thermal behavior of different date palm residues: characterization and devolatilization kinetics under inert and oxidative atmospheres. Energy 44, 702-709.
 Kholif A., Farahat E., Hanafy M., Kholif S., El-Sayed R., 2015. Utilization of cellulolytic enzymes to improve the nutritive value of date kernels and the investigation of the impact of adding these enzymes to lactating goat's diets on rumen fermentation and nutrients digestibility. Asian Journal of Animal Science 9, 441-447.
 Lawal T., Iyayi E., Adeniyi B., Adaramoye O., 2010. Biodegradation of palm kernel cake with multienzyme complexes from fungi and its feeding value for broilers. International Journal of Poultry Science 9, 695-701.
 Li W., Bai J., Li Y., Qin Y., Yu D., 2014. Effects of Bacillus subtilis on meat quality, nutrient digestibility, and serum biochemical parameters of broilers. Chinese Journal of Veterinary Science 34, 1682-1685.
 Makar H., 2004. Recent advances in the in vitro gas method for evaluation of nutritional quality of feed resources. FAO Animal Production and Health Paper 55-88.
 Malik C.P., Singh M., 1980. Plant enzymology and histo-enzymology. Kalyani Publishers, New Delhi, India.
 Marini A., Daud M., Noraini S., Jame ah H., Azahan E.E., 2005. Performance of locally isolated microorganism in degrading palm kernel cake (PKC) fibre and improving the nutritional value of fermented PKC. Journal of Tropical Agriculture and Food Science 33, 311-319.
 Menke K., Raab L., Salewski A., Steingass H., Fritz D. et al. 1979. The estimation of the digestibility and metabolizable energy content of ruminant feedingstuffs from the gas production when they are incubated with rumen liquor in vitro. The Journal of Agricultural Science 93, 217-222.
 Menke K.H., 1988. Estimation of the energetic feed value obtained from chemical analysis and in vitro gas production using rumen fluid. Animal Research and Development 28, 7-55.
 Mirnawati, Djulardi A., Marlida Y., 2013. Improving the Quality of Palm Kernel Cake Through Fermentation by Eupenicillium javanicum as Poultry Ration. Pakistan Journal of Nutrition 12, 1085-1088.
 Mirnawati Y.R., Marlida Y., Kompiang I.P., 2011. Evaluation of palm kernel cake fermented by Aspergillus niger as substitute for soybean meal protein in the diet of broiler. International Journal of Poultry Science 10, 537-541.
 Obernberger I., Thek G., 2004. Physical characterisation and chemical composition of densified biomass fuels with regard to their combustion behaviour. Biomass and Bioenergy 27, 653-669.
 Obese F., Osafo E., Okai D., 2001. Evaluation of the feeding value of palm press fibre using in vitro digestibility techniques. Tropical Animal Health and Production 33, 165-172.
 Ong L., Abd-Aziz S., Noraini S., Karim M., Hassan M., 2004. Enzyme production and profile by Aspergillus niger during solid substrate fermentation using palm kernel cake as substrate. Applied Biochemistry and Biotechnology 118, 73-79.
 Ørskov E., McDonald I., 1979. The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage. The Journal of Agricultural Science 92, 499-503.
 Pangsri P., Pangsri P., 2017. Mannanase enzyme from Bacillus subtilis P2-5 with waste management. International Journal of Poultry Science 138, 343-347.
 Pinto G.A., Leite S.G., Terzi S.C., Couri S., 2001. Selection of tannase-producing Aspergillus niger strains. Brazilian Journal of Microbiology 32, 24-26.
 Rad A.R., Ahmadi F., Mohammadabadi T., Ziaee E., Polikarpov I., 2015. Combination of sodium hydroxide and lime as a pretreatment for conversion of date palm leaves into a promising ruminant feed: an optimization approach. Waste and Biomass Valorization 6, 243-252.
 Ramin M., Alimon A., Ivan M., 2010. Effects of fungal treatment on the in vitro digestion of palm kernel cake. Livestock Research for Rural Development 22.
 Rezaeenia A., Naserian A., Valizadeh R., Tahmasbi A., 2014. Chemical composition, DM, and NDF degradation kinetics in rumen of eleven different date pits. Annual Research & Review in Biology 3524-3531.
 Rizal Y., Nuraini, Mirnawati, Mahata M.E., 2013. Comparisons of Nutrient Contents and Nutritional Values of Palm Kernel Cake Fermented by Using Different Fungi. Pakistan Journal of Nutrition 12, 943-948.
 SAS. 2003. SAS user's guide: Statistics. Sas Inst
 Schallmey M., Singh A., Ward O.P., 2004. Developments in the use of Bacillus species for industrial production. Canadian Journal of Microbiology 50, 1-17.
 Shawrang P., Sadeghi A., Ahmadpanah J., 2013. Ruminal degradation kinetics of wheat straw irradiated by high doses of electron beam. Iranian Journal of Applied Animal Science 25-29.
 Shelton J., Dean D., Southern L., Bidner T., 2005. Effect of protein and energy sources and bulk density of diets on growth performance of chicks. Poultry Science 84, 1547-1554.
 Sinurat A.P., T P., T P., 2013. Improving nutrient values of palm kernel cake (PKC) by reducing shell contamination and enzymes supplementation. Jurnal Ilmu Ternak dan Veteriner 18, 27-33.
 Sommart K., Parker D., Rowlinson P., Wanapat M., 2000. Fermentation characteristics and microbial protein synthesis in an in vitro system using cassava, rice straw, and dried ruzi grass as substrates. Asian-Australasian Journal of Animal Sciences 13, 1084-1093.
 Squires M., Naber E., Toelle V., 1992. The effects of heat, water, acid, and alkali treatment of tomato cannery wastes on growth, metabolizable energy value, and nitrogen utilization of broiler chicks. Poultry Science 71, 522-529.
 Sun S., Sun S., Cao X., Sun R., 2016. The role of pretreatment in improving the enzymatic hydrolysis of lignocellulosic materials. Bioresource Technology 199, 49-58.
 Theodorou M.K., Williams B.A., Dhanoa M.S., McAllan A.B., France J., 1994. A simple gas production method using a pressure transducer to determine the fermentation kinetics of ruminant feeds. Animal Feed Science and Technology 48, 185-197.
 Van Soest P.v., Robertson J., Lewis B., 1991. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science 74, 3583-3597.
 van Zyl P.J., Moodley V., Rose S., Roth R., Van Zyl W., 2009. Production of the Aspergillus aculeatus endo-1, 4-β-mannanase in A. niger. Journal of Industrial Microbiology & Biotechnology 36, 611-617.
 Yadi P., Yana S., 2011. The influence of palm kernel cake and rice bran fermentation product mixture to the broiler carcass quality. International Journal of Science and Engineering 2, 1-3.
 Yousuf R.G., Winterburn J.B., 2016. Date seed characterisation, substrate extraction, and process modelling for the production of polyhydroxybutyrate by Cupriavidus necator. Bioresource Technology 222, 242-251.