TY - JOUR

T1 - The potential of the cyanobacterium Leptolyngbya ohadii as inoculum for stabilizing bare sandy substrates

AU - Mugnai, Gianmarco

AU - Rossi, Federico

AU - Felde, Vincent John Martin Noah Linus

AU - Colesie, Claudia

AU - Büdel, Burkhard

AU - Peth, Stephan

AU - Kaplan, Aaron

AU - De Philippis, Roberto

N1 - Funding information: The authors wish to thank Andrea Simiani (DISPAA, University of Florence) for the help with some of the instrumental analysis performed for this work; Nadav Oren (Hebrew University of Jerusalem) for the help with sand collection in the Negev Desert; Dr Sonia Chamizo De La Piedra (DISPAA, University of Florence) for assistance during aggregate stability measurement, and Lisa Cangioli (DISPAA, University of Florence) for the help in some of the analytical procedures. This research was partially supported by the Italian Ministry of Foreign Affairs in the frame of the Italy-Israel Scientific and Technological Cooperation Agreement (project NATURALWATER). The Authors wish also to thank the Chief Editor of SBB, Joann Whalen, and the anonymous Reviewers for their extensive efforts that greatly helped to improve this manuscript. The authors wish to thank Andrea Simiani (DISPAA, University of Florence) for the help with some of the instrumental analysis performed for this work; Nadav Oren (Hebrew University of Jerusalem) for the help with sand collection in the Negev Desert; Dr Sonia Chamizo De La Piedra (DISPAA, University of Florence) for assistance during aggregate stability measurement, and Lisa Cangioli (DISPAA, University of Florence) for the help in some of the analytical procedures. This research was partially supported by the Italian Ministry of Foreign Affairs in the frame of the Italy-Israel Scientific and Technological Cooperation Agreement (project NATURALWATER). The Authors wish also to thank the Chief Editor of SBB, Joann Whalen, and the anonymous Reviewers for their extensive efforts that greatly helped to improve this manuscript.

PY - 2018/12

Y1 - 2018/12

N2 - Soil inoculation with cyanobacteria to promote the formation of biocrusts is considered a potential eco-friendly method to counteract desertification spread in drylands. Research is needed to increase the number of proficient cyanobacterial strains, selected for their capability to survive in harsh conditions and to form stable biocrusts quickly. We hereby present a microcosm study to assess the capability of Leptolyngbya ohadii, native to the Negev Desert, to form biocrusts on sand collected in the same environment, during a three-month incubation period. Inoculation was carried out in sand-filled microcosms without nutrient addition and a limited water supply (equivalent to desert dew input). Parameters related to biocrusts growth and to their physico-chemical attributes were measured, and the exopolysaccharides (EPS) synthesized by the strain during biocrust formation were quantified and characterized. After 15 days of incubation, L. ohadii was able to form biocrusts with a thickness and a physical stability superior to other test strains of cyanobacteria, and typical of much older natural biocrusts. Biocrust characteristics were dependent on the synthesis of EPS, and on the capability to migrate in the sand, stabilizing sand aggregates at different locations within the microcosms. In contrast to other tested strains, L. ohadii produced compositionally complex EPS during the entire incubation period despite the lack of nutrients, producing biocrusts with an amphiphilic extracellular matrix, a character effective in conferring stability to sand aggregates, chelating nutrients and maintaining hydration. Overall, this study shows that L. ohadii is a promising inoculant that may be considered to promote the formation of biocrusts in natural desert settings.

AB - Soil inoculation with cyanobacteria to promote the formation of biocrusts is considered a potential eco-friendly method to counteract desertification spread in drylands. Research is needed to increase the number of proficient cyanobacterial strains, selected for their capability to survive in harsh conditions and to form stable biocrusts quickly. We hereby present a microcosm study to assess the capability of Leptolyngbya ohadii, native to the Negev Desert, to form biocrusts on sand collected in the same environment, during a three-month incubation period. Inoculation was carried out in sand-filled microcosms without nutrient addition and a limited water supply (equivalent to desert dew input). Parameters related to biocrusts growth and to their physico-chemical attributes were measured, and the exopolysaccharides (EPS) synthesized by the strain during biocrust formation were quantified and characterized. After 15 days of incubation, L. ohadii was able to form biocrusts with a thickness and a physical stability superior to other test strains of cyanobacteria, and typical of much older natural biocrusts. Biocrust characteristics were dependent on the synthesis of EPS, and on the capability to migrate in the sand, stabilizing sand aggregates at different locations within the microcosms. In contrast to other tested strains, L. ohadii produced compositionally complex EPS during the entire incubation period despite the lack of nutrients, producing biocrusts with an amphiphilic extracellular matrix, a character effective in conferring stability to sand aggregates, chelating nutrients and maintaining hydration. Overall, this study shows that L. ohadii is a promising inoculant that may be considered to promote the formation of biocrusts in natural desert settings.

KW - Biocrusts

KW - EPS

KW - Cyanobacteria

KW - Inoculation

KW - Soil rehabilitation

KW - Arid environments

UR - http://www.scopus.com/inward/record.url?scp=85053027105&partnerID=8YFLogxK

U2 - 10.1016/j.soilbio.2018.08.007

DO - 10.1016/j.soilbio.2018.08.007

M3 - Article

VL - 127

SP - 318

EP - 328

JO - Soil biology & biochemistry

JF - Soil biology & biochemistry

SN - 0038-0717

ER -