A SUBSTRATE-INDUCED RESPIRATION (SIR) METHOD FOR MEASUREMENT OF FUNGAL AND BACTERIAL BIOMASS ON PLANT RESIDUES
A SUBSTRATE-INDUCED RESPIRATION (SIR) METHOD FOR MEASUREMENT OF FUNGAL AND BACTERIAL BIOMASS ON PLANT RESIDUES
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DOI：
10.1016/0038-0717(90)90002-h
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发表时间：
1990-01-01
影响因子：
9.7
通讯作者：
HARGROVE, WL
中科院分区：
文献类型：
--
作者：
BEARE, MH;NEELY, CL;HARGROVE, WL
基质诱导呼吸（SIR）的方法进行了修改和调整，以测量真菌，细菌和总微生物的葡萄糖诱导的呼吸和潜在的活性微生物生物量腐烂的植物残留物的不同组合物的贡献。将来自自然和农业生态系统的分解残留物切碎并过筛，以包括>1 mm的部分，用于在连续流通呼吸系统上进行常规SIR分析。对SIR方法进行了最优化，包括样品大小（0.5-1.0 g干重）、葡萄糖浓度（80 mg g-1）、抗生素浓度（16 mg链霉素g-1; 80 mg放线菌酮g-1）、总溶液体积（5 ml）、抗生素预温育条件（4 ℃下12 h）和加入葡萄糖后的总测定时间（2-3 h）。通过体外和原位暴露于抗生素下的混合残留物-微生物种群的琼脂平板培养实验，分析了抗生素对靶种群的选择性。结果支持SIR优化的浓度，并强调了独立分析抗生素选择性的重要性。真菌、细菌和总SIR（μ g CO2-C g-1干残留物h-1）的测量值分别与总（r2 = 0.91）和FDA活性（r2 = 0.93）真菌生物量、细菌生物量（r2 = 0.87）和总微生物生物量（r2 = 0.91）的生物体积衍生估计值线性相关（P < 0.001）。真菌与细菌的SIR比（1.6：1至2.5：1）强调了真菌在植物残留物腐烂的早期阶段（≤ 3周）中的优势。植物残体SIR率是土壤的38-600倍。来自植物残留物的生物量特异性SIR率（72 ng CO2-C h-1 μ g-1生物量-C）比来自土壤SIR的报道高5-6倍。这些发现表明，与土壤相比，植物残体上的微生物生物量更大，生理活性微生物的比例也更高。
The substrate-induced respiration (SIR) method was modified and adapted to measure fungal, bacterial and total microbial contributions to glucose-induced respiration and the potentially active microbial biomass on decaying plant residues of differing composition. Decomposing residues from natural and agricultural ecosystems were chopped and sieved to include the >1 mm fraction for routine SIR analyses on a continuous flow-through respiration system. SIR procedures were optimized for sample size (0.5-1.0 g dry wt), glucose concentration (80 mg g-1), antibiotic concentrations (16 mg streptomycin g-1; 80 mg cycloheximide g-1), total solution volume (5 ml), antibiotic preincubation conditions (12 h at 4.degree.C), and total assay time following glucose addition (2-3 h). Analyses of antibiotic selectivities for target populations were made from agar plate culture experiments with mixed residue-microbial populations under in vitro and in situ exposure to antibiotics. The results support those concentrations optimized by SIR and emphasize the importance of independent analysis of antibiotic selectivity. Measures of fungal, bacterial and total SIR (.mu.g CO2-C g-1 dry residue h-1) were linearly correlated (P < 0.001) with biovolume-derived estimates of total (r2 = 0.91) and FDA-active (r2 = 0.93) fungal biomass, bacterial biomass (r2 = 0.87) and total microbial biomass (r2 = 0.91), respectively. Fungal to bacterial SIR ratios (1.6:1 to 2.5:1) emphasize the dominance of fungi in the early stages of plant residue decay (.ltoreq.3 weeks). Plant residue SIR rates were 38-600 times greater than those of soils. Biomass specific SIR rates from plant residues (72 ng CO2-C h-1 .mu.g-1 biomass-C) were 5-6 times higher than those reported from soil SIR. These findings suggest both a larger microbial biomass as well as a much higher proportion of physiologically active microorganisms on plant residues as compared to soils.