Ben Mabrouk Sameh, Ben Hadj Hmida Bouthaina, Sallami Wejdene, Dhaouadi Salma, Varzakas Theodoros, Smaoui Slim
Laboratory of Biochemistry and Enzymatic Engineering of Lipases, National Engineering School of Sfax, University of Sfax, BP 1173, Sfax 3038, Tunisia.
Department of Food Science and Technology, University of the Peloponnese, Antikalamos, 24100 Kalamata, Greece.
Microorganisms. 2025 Jul 3;13(7):1571. doi: 10.3390/microorganisms13071571.
This study highlights waste bread (WB) as a novel, cost-effective, and nutrient-rich substrate for microbial growth, offering a sustainable alternative to conventional media. As a renewable resource, WB promotes the circular economy by reducing food waste and encouraging biotechnological innovation. The incorporation of WB into microbial culture media enhanced the growth of various reference strains (, , , and ), with at least a two-fold increase compared to conventional Luria-Bertani (LB) medium. Moreover, combining 2% WB with diluted LB (1/10) reduced medium costs by up to 90%. Furthermore, it was confirmed that 1% WB can effectively replace starch during the screening of amylolytic strains. Applying a fractional factorial design, the production of amylase by sp. BSS (Amy-BSS) was enhanced 15-fold. An analysis of the Pareto diagram revealed that WB was the most significant factor. Additionally, Amy-BSS was applied to hydrolyze polysaccharides in WB, enabling the generation of high-value-added products in food processing. This hydrolysis process yielded 4.6 g/L of fermentable sugars from 1% WB. Evaluating the economic feasibility of WB valorization into value-added products elucidates potential pathways for cost reduction and enhanced environmental sustainability, thereby positioning WB as a viable tool for sustainable development.
本研究强调废弃面包（WB）是一种用于微生物生长的新型、经济高效且营养丰富的底物，为传统培养基提供了一种可持续的替代方案。作为一种可再生资源，WB通过减少食物浪费和鼓励生物技术创新来促进循环经济。将WB纳入微生物培养基可促进各种参考菌株（、、和）的生长，与传统的Luria-Bertani（LB）培养基相比，至少增加两倍。此外，将2%的WB与稀释的LB（1/10）混合可将培养基成本降低多达90%。此外，在筛选淀粉酶菌株时，证实1%的WB可有效替代淀粉。应用分数析因设计，菌株BSS（Amy-BSS）产生淀粉酶的量提高了15倍。帕累托图分析表明，WB是最显著的因素。此外，Amy-BSS被用于水解WB中的多糖，从而在食品加工中能够生成高附加值产品。该水解过程从1%的WB中产生了4.6 g/L的可发酵糖。评估将WB转化为高附加值产品的经济可行性，阐明了降低成本和增强环境可持续性的潜在途径，从而将WB定位为可持续发展的可行工具。
