Diversity, role in decomposition, and succession of zoosporic fungi and straminipiles on submerged decaying leaves in a woodland stream

Abstract

Leaf litter is a very important primary source of energy in woodland streams. Decomposition of leaf litter is a process mediated by many groups of microorganisms which release extracellular enzymes for the degradation of complex macromolecules. In this process, true fungi and straminipiles are considered to be among the most active groups, more active than the bacteria, at least during the early stages of the process. Colonization increases the quality of the leaves as a food resource for detritivores. In this way, matter and energy enter detritusbased food chains. Previously, aquatic hyphomycetes were considered to be the major fungal group responsible for leaf litter decomposition. Although zoosporic fungi and straminipiles are known to colonize and decompose plant tissues in various environments, there is scant information on their roles in leaf decomposition. This study focuses on the communities of zoosporic fungi and straminipiles in a stream which are involved in the decomposition of leaves of two plant species, Ligustrum lucidum and Pouteria salicifolia, in the presence of other groups of fungi. A characteristic community dominated by Nowakowskiella elegans, Phytophthora sp., and Pythium sp. was found. Changes in the fungal community structure over time (succession) was observed: terrestrial mitosporic fungi appeared during the early stages, zoosporic fungi, straminipiles, and aquatic Hyphomycetes in early-to-intermediate stages, while representatives of the phylum Zygomycota were found at early and latest stages of the decomposition. These observations highlight the importance of zoosporic fungi and straminipiles in aquatic ecosystems.

Aquatic Fungi and Straminipilous Organisms in the Lakes of the Ełckie District

“…Fungi and straminipilous organisms commonly occur in water reservoirs of various types and have a substantial effect on the functioning of the hydro-ecosystems [17][18][19][20]. They play a major role in inland waters, are the source of food for numerous invertebrates, and mineralize organic matter -thus facilitating the process of self-purification.…”

“…Most fungal species were isolated from water samples obtained from lakes Łaśmiady (23), Szarek (22), and Krzywe (20). The hydrochemical analysis showed that these water basins are characterized by high content of O 2 and moderate concentrations of biogenic compounds (especially nitrates and phosphates).…”

Oomycetes (Oomycota) from Maranhão State, Brazil1

“…Saprobic species have extensive enzymatic capacity, with the ability to degrade a wide range of vegetal and animal substrates such as cellulose (algae and plant debris), keratin (snake skin, hair and feather), chitin (exoskeleton of crustaceans and insects), lignin (dead tissue of woody plants) and sporopollenin (pollen grains). Saprotrophic species are abundantly found in decaying plant material, but their occurrence and frequency are underestimated unless specific techniques are applied for their study (Hawksworth 2004, Marano et al 2011.…”

Diversidade, Abundância E Frequência De Oomycota, Blastocladiomycota E Chytridiomycota Em Lagoas De Teresina, Piauí

“…No Brasil, esses trabalhos concentram suas informações para o estado de São Paulo, onde os estudos foram pioneiros sobre a diversidade (Joffily 1947, Beneke e Rogers 1962); sistemática (Furtado 1965), distribuição geográfica (Milanez 1984, Pires-Zottarelli 1990, Milanez et al 1995, 1996, Pires-Zottarelli et al 1995, 1996a, 1996b, Rocha e Pires-Zottarelli 2002, Gomes et al 2003), e ecologia (Milanez e Trufen 1984, Baptista et al 2004, Shearer et al 2007, Marano et al, 2008, 2011, Nascimento e Pires-Zottarelli 2009, Nascimento 2010, Jesus et al 2013, Jeronimo et al 2015.…”