The impact of biofumigation and chemical fumigation methods on the structure and function of the soil microbial community.
Biofumigation (BIOF) is carried out mainly by the incorporation of brassica plant parts into the soil, and this fumigation activity has been linked to their high glucosinolate (GSL) content. GSLs are hydrolyzed by the endogenous enzyme myrosinase to release isothiocyanates (ITCs). A microcosm study was conducted to investigate the effects induced on the soil microbial community by the incorporation of broccoli residues into soil either with (BM) or without (B) added myrosinase and of chemical fumigation, either as soil application of 2-phenylethyl ITC (PITC) or metham sodium (MS). Soil microbial activity was evaluated by measuring fluorescein diacetate hydrolysis and soil respiration. Effects on the structure of the total microbial community were assessed by phospholipid fatty acid analysis, while the impact on important fungal (ascomycetes (ASC)) and bacterial (ammonia-oxidizing bacteria (AOB)) guilds was evaluated by denaturating gradient gel electrophoresis (DGGE). Overall, B, and to a lesser extent BM, stimulated microbial activity and biomass. The diminished effect of BM compared to B was particularly evident in fungi and Gram-negative bacteria and was attributed to rapid ITC release following the myrosinase treatment. PITC did not have a significant effect, whereas an inhibitory effect was observed in the MS-treated soil. DGGE analysis showed that the ASC community was temporarily altered by BIOF treatments and more persistently by the MS treatment, while the structure of the AOB community was not affected by the treatments. Cloning of the ASC community showed that MS application had a deleterious effect on potential plant pathogens like Fusarium, Nectria, and Cladosporium compared to BIOF treatments which did not appear to inhibit them. Our findings indicate that BIOF induces changes on the structure and function of the soil microbial community that are mostly related to microbial substrate availability changes derived from the soil amendment with fresh organic materials.
Omirou
Michalis
M
Department of Natural Resources and Agricultural Engineering, Laboratory of Soils and Agricultural Chemistry, Agricultural University of Athens, 75 Iera Odos Str, 11855, Athens, Greece.
Rousidou
Constantina
C
Bekris
Fotios
F
Papadopoulou
Kalliope K
KK
Menkissoglou-Spiroudi
Urania
U
Ehaliotis
Constantinos
C
Karpouzas
Dimitrios G
DG
D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000378:metabolism*; D001937:Brassica / Q000737:chemistry; D004952:Esters / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D005452:Fluoresceins / Q000032:analysis / Q000378:metabolism; D005651:Fumigation; D005658:Fungi / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010575:Pesticides / Q000494:pharmacology*; D010743:Phospholipids / Q000032:analysis; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil / Q000032:analysis / Q000737:chemistry; D012988:Soil Microbiology
D004952:Esters; D005227:Fatty Acids; D005452:Fluoresceins; D010575:Pesticides; D010743:Phospholipids; D012336:RNA, Ribosomal, 16S; D012987:Soil; C018506:diacetylfluorescein
FEMS Microbiol Ecol. 2005 Jul 1;53(2):245-53
16329944
Mycologia. 2003 Sep-Oct;95(5):820-6
21148989
FEMS Microbiol Ecol. 2009 Dec;70(3):388-401
19799632
Environ Microbiol. 2008 Nov;10(11):2931-41
18973620
Phytopathology. 2006 Jan;96(1):68-79
18944206
Mol Biol Evol. 1987 Jul;4(4):406-25
3447015
J Biotechnol. 1999 Oct 8;75(2-3):187-94
10553657
Mycol Res. 2003 Jun;107(Pt 6):707-16
12951797
Environ Toxicol Chem. 2001 Nov;20(11):2462-8
11699770
Appl Environ Microbiol. 2001 Oct;67(10):4554-9
11571155
Appl Environ Microbiol. 1997 Apr;63(4):1489-97
9097446
Annu Rev Microbiol. 2001;55:485-529
11544365
FEMS Microbiol Ecol. 2002 Mar 1;39(3):183-91
19709198
FEMS Microbiol Ecol. 2003 Mar 1;43(2):263-70
19719687
Appl Environ Microbiol. 2000 Dec;66(12):5410-8
11097922
FEMS Microbiol Ecol. 2006 Jun;56(3):482-93
16689879
Appl Environ Microbiol. 2001 Jul;67(7):3245-57
11425748
Microb Ecol. 2009 Nov;58(4):715-27
19440648
Appl Environ Microbiol. 2002 Jan;68(1):20-30
11772604
Microb Ecol. 2005 Jan;49(1):83-93
15690230
Phytochemistry. 2001 Jan;56(1):5-51
11198818
Pest Manag Sci. 2005 Nov;61(11):1043-51
15986402
Appl Environ Microbiol. 2000 Dec;66(12):5368-82
11097916
FEMS Microbiol Lett. 2005 Sep 1;250(1):33-8
16043309
FEMS Microbiol Lett. 1994 Jul 15;120(3):363-7
8076810
Trends Plant Sci. 2002 Jun;7(6):263-70
12049923
J Agric Food Chem. 2009 Sep 9;57(17):7706-11
19722704