Fusarium equiseti LPSC 1166 and its in vitro role in the decay of Heterostachys ritteriana leaf litter

Abstract

The role of microorganisms in litter degradation in arid and semi-arid zones, where soil and water salinization is one of the main factors limiting carbon turnover and decay, remains obscure. Heterostachys ritteriana (Amaranthaceae), a halophyte shrub growing in arid environments such as "Salinas Grandes" (Córdoba, Argentina), appears to be the main source of organic matter in the area. Little is known regarding the microorganisms associated with H. ritteriana, although they are a potential source of enzymes such as cellulolytic ones, which might be important in biotechnological fields such as bioethanol production using ionic liquids. In the present study, by studying the microbiota growing on H. ritteriana leaf litter in "Salinas Grandes," we isolated the cellulolytic fungus Fusarium equiseti LPSC 1166, which grew and degraded leaf litter under salt stress. The growth of this fungus was a function of the C substrate and the presence of NaCl. Although in vitro the fungus used both soluble and polymeric compounds from H. ritteriana litter and synthesized extracellular β-1,4 endoglucanases, its activity was reduced by 10% NaCl. Based on these results, F. equiseti LPSC 1166 can be described as a halotolerant cellulolytic fungus most probably playing a key role in the decay of H. ritteriana leaf litter in "Salinas Grandes."

Multiple riparian–stream connections are predicted to change in response to salinization

“…Rising salinity can increase fungal sporulation supporting the hypothesis that fungi allocate more energy to reproduction in the presence of some salts, in this case HCO À 3 [82]. Conversely, rising salinity from NaCl may also induce fungal sporulation for some species and a decline in extracellular cellulolytic activity in others [41,83]. The effects of low-level salinization are even less understood [69].…”

Soil mycobiota under managed and unmanaged forests of <i>Nothofagus pumilio</i> in Tierra del Fuego, Argentina

“…They can establisher new biotic interactions that often result in changes to the environment and activate inducible metabolic pathways that allow their growth under stressful conditions such as when nutrient resources are scarce (Troncozo et al 2015). This includes phenotypic plasticity according to available organic substrates and synthesis of lytic enzymes involved in soil formation, which have adaptive and ecological significance (Franco et al 2018). Lin et al (2016) reported that the soil mycobiota of a Taiwanese Cryptomeria japonica forest regained system stability and recovered from tree thinning disturbance in a relatively short period of time.…”