Shahin Shokooh, Mohammadi-Sichani Maryam, Rezayatmand Zahra
Department of Microbiology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran.
Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran.
Curr Microbiol. 2023 Mar 15;80(5):137. doi: 10.1007/s00284-022-03153-4.
Spent mushroom compost (SMC) is a favored waste because of its nutrients for plant growth and useful microbial communities. The aim of this study was to isolate the lead resistant bacteria from SMC and to evaluate the effects of SMC extract on the growth and biochemical parameters of safflower under lead stress including fresh and dry weights, photosynthetic pigments, protein content, and enzymatic activities. Four bacterial strains including Bacillus licheniformis, Bacillus cereus, Bacillus aerius, and Brevibacterium frigoritolerans were identified in the SMC extract; from which B. licheniformis offer the most resistance to lead. The highest total chlorophyll content of the plant was seen by treatment with 100 mM lead; the highest carotenoid content observed by treatment with 100 mM lead in association with 10% and 5% SMC extract; and the highest increase in protein content was seen in the presence of 5% SMC. The safflower seeds germination was reached the highest level in the presence of 20% SMC extract associated with 50 and 100 mM lead. The highest dry weights of the plant roots (33%) and stems (85%) were shown in the presence of 100 mM lead in association with 5% SMC extract. The highest antioxidant enzymes activity was seen by polyphenol oxidase (0.135 OD/min/mg) in the presence of 100 mM lead in association with 10% SMC extract. It is concluded that by induction of lead bioremediation via improving lead resistant bacterial communication, and the addition of 10-20% SMC extract to the agricultural soil, safflower may undergo the lead stress.
废蘑菇堆肥（SMC）因其富含植物生长所需养分及有益微生物群落而成为一种理想的废弃物。本研究旨在从SMC中分离出抗铅细菌，并评估SMC提取物对铅胁迫下红花生长及生化参数的影响，这些参数包括鲜重和干重、光合色素、蛋白质含量及酶活性。在SMC提取物中鉴定出了4种细菌菌株，分别为地衣芽孢杆菌、蜡样芽孢杆菌、产气芽孢杆菌和耐冷短杆菌；其中地衣芽孢杆菌对铅的抗性最强。用100 mM铅处理时，植物的总叶绿素含量最高；用100 mM铅与10%和5%的SMC提取物联合处理时，类胡萝卜素含量最高；在5% SMC存在的情况下，蛋白质含量增加最多。在20% SMC提取物与50和100 mM铅联合存在的情况下，红花种子发芽率达到最高水平。在100 mM铅与5% SMC提取物联合存在的情况下，植物根（33%）和茎（85%）的干重最高。在100 mM铅与10% SMC提取物联合存在的情况下，多酚氧化酶的抗氧化酶活性最高（0.135 OD/分钟/毫克）。研究得出结论，通过改善抗铅细菌间的通讯来诱导铅生物修复，并向农业土壤中添加10 - 20%的SMC提取物，红花可能会承受铅胁迫。
