Premium
Bacteria related to the nitrogen cycle in salt‐affected soils of Argentina
Author(s) -
Arias Renée Silvia,
Galizzi Fernando Angel,
Sagardoy Marcelo Antonio,
Peinemann Norman,
Ares Adrián
Publication year - 1998
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/(sici)1521-4028(199807)38:3<159::aid-jobm159>3.0.co;2-3
Subject(s) - bacteria , soil water , organic matter , abundance (ecology) , soil ph , chemistry , salinity , soil salinity , halophile , azotobacter , microorganism , environmental chemistry , food science , botany , zoology , biology , ecology , genetics
We studied abundance as well as some morphological and physiological characteristics of six groups of bacteria (total aerobic, proteolytics, ammonifiers, nitrifiers, denitrifiers and bacteria from N‐free medium) in six toposequences with salt‐affected soils in the semiarid region of Argentina. Abundance of most groups of bacteria was positively related with soil organic matter content and inversely related with soil pH (within a pH range of 7 to 10.5), exchangeable sodium and soil depth. CaCO 3 and electric conductivity were only related to the abundance of some bacterial groups in A and C horizons. Predictive equations for each toposequence explained between 31 and 89% of the variance in bacterial abundance. Multivariate relationships between bacterial groups and soil factors also indicated that organic matter content and pH were more important factors to influence microbial abundance than salt content in these soils. All the groups examined were present in the salt crusts which reached electric conductivity values of up to 216 dS/m. Bacillus spp. and coryneform bacteria prevailed among the 537 strains isolated from A to C horizons. Neither Azotobacter nor halophilic bacteria were found with the culture media utilized. One third of the 42 strains which grew in N‐free medium utilized D ‐glucose and 55% did not use the sugars tested. All bacterial groups were more affected by NaCl than by Na 2 SO 4 in laboratory tests with no groups surviving NaCl concentrations of 100 g/l.