Candida ficus sp. nov., a novel yeast species from the gut of Apriona germari larvae

Abstract

A novel yeast species is described based on three strains from the gut of wood-boring larvae collected in a tree trunk of Ficus carica cultivated in parks near Nanyang, central China. Phylogenetic analysis based on sequences of the D1/D2 domains of the large subunit rRNA gene showed that these strains occurred in a separate clade that was genetically distinct from all known ascomycetous yeasts. In terms of pairwise sequence divergence, the novel strains differed by 15.3 % divergence from the type strain of Pichia terricola, and by 15.8 % divergence from the type strains of Pichia exigua and Candida rugopelliculosa in the D1/D2 domains. All three are ascomycetous yeasts in the Pichia clade. Unlike P. terricola, P. exigua and C. rugopelliculosa, the novel isolates did not ferment glucose. Their larvae usually bore to the roots along the xylem and pith in the stems, resulting in poor plant growth and vigour, and premature ageing, thus affecting fruit yield.In a survey of the diversity of yeasts vectored by this pest, we have isolated three strains of a novel ascomycetous yeast species from wood-boring larvae collected in central China. These yeasts are physiologically similar to Pichia terricola, Pichia exigua and other species in the Pichia clade such as Candida rugopelliculosa, which are characterized by the fermentation and assimilation of only a few carbon compounds and are almost indistinguishable physiologically from one another (Lachance et al., 2011). However, the sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene of these strains are unique and divergent from those of any previously described yeast species. In this report, a novel anamorphic ascomycetous yeast species is proposed, Candida ficus sp. nov., to accommodate these isolates.Three strains, STN-8 T , STN-57 and STN-115, were isolated in November 2011 from the gut of three different Apriona germari larvae. The samples were collected from the tree trunks of Ficus carica Linn. cultivated in two separate parks located near Nanyang, which is located in a warm, temperate zone with a monsoon-influenced semi-humid continental climate in Henan province, central China. Strains STN-8 T and STN-57 were isolated from two individuals of the insect larvae collected at White River Wetland Park, whereas strain STN-115 was from one sample of an insect larva collected at Dushan Forest Park; the two parks are separated from each other by a distance of 10.2 km.Methods for yeast isolation were as detailed by Nguyen et al. (2006) and Suh et al. (2004). The insects were usually placed in Petri dishes for 1-3 days without food prior to dissection. Withholding food helps to eliminate some contaminating organisms that might be isolated from the gut. Surface disinfection was performed by submersion in 95 % ethanol for 1-2 min. The alcohol wash was followed by a 0.7 % saline rinse. The insect gut was removed aseptically under a dissecting microscope and gut segments were streaked on acidified YM agar plates (0.3 % yeast extract, 0.3 % malt extract, 0.5 % pepto...

Saccharomyces cerevisiae – Insects Association: Impacts, Biogeography, and Extent

“…Similarly, S. cerevisiae has not been found in butterflies ( n = 11 species in different locations) and moths ( n = 4) ( Suh et al, 2006 ; Witzgall et al, 2012 ; Ravenscraft et al, 2018 ). Interestingly, only the 0.03% of beetles, which have been widely investigated ( n = 236), bear S. cerevisiae ( Kurtzman and Robnett, 1998 ; Lachance et al, 2001a , b , 2006 ; Six, 2003 ; Suh and Blackwell, 2004 , Suh et al, 2005 , 2006 , 2007 , 2013 ; Delalibera et al, 2005 ; Nguyen et al, 2006 ; Rosa et al, 2007 ; Rivera et al, 2009 ; de Vega et al, 2012 ; Hui et al, 2012 ; Toki et al, 2012 ; Freitas et al, 2013 ; Kaltenpoth and Steiger, 2013 ; Ninomiya et al, 2013 ; Urbina et al, 2013 ; Cline et al, 2014 ; Ren et al, 2014 , 2015 ; Liu et al, 2016 ; Tanahashi and Hawes, 2016 ; Wang et al, 2016 ; Briones-Roblero et al, 2017 ; Chai et al, 2019 ). Similarly, bees only accidentally bear S. cerevisiae , with only 1 occurrence over 21 reported cases ( Sandhu and Waraich, 1985 ; Lachance et al, 2003 ; Rosa et al, 2003 ; Daniel et al, 2013 ; Charron et al, 2014 ; Saksinchai et al, 2015 ).…”

Molecular Phylogenetic Analysis Reveals the New Genus Hemisphaericaspora of the Family Debaryomycetaceae

“…In a study of yeasts from wood-boring insects, we isolated a large number of yeasts mainly from the digestive tract of beetles as well as from related substrates, including rotted wood, frass and galleries [13], [14]. The majority of the yeast belonged to several major clades in the Saccharomycotina; some of these species have been identified as novel species in earlier papers [13]–[16].…”

Wickerhamiella allomyrinae f.a., sp. nov., a yeast species isolated from the gut of the rhinoceros beetle Allomyrina dichotoma

“…The majority of the yeasts belonged to several major clades in the subphylum Saccharomycotina; some of these species have been identified as novel species in earlier papers (Hui et al, 2012(Hui et al, , 2013a(Hui et al, , 2013bChen et al, 2013). Amongst the insect associates, we focused on two strains of an asexual ascomycetous yeast species from the gut of the rhinoceros beetle Allomyrina dichotoma in China.…”

“…During a study of yeasts associated with insects, we isolated a large number of yeasts from the digestive tract of insects as well as from related substrates, including rotting wood, frass and galleries (Chen et al, 2013;Hui et al, 2013). The majority of the yeasts belonged to several major clades in the subphylum Saccharomycotina; some of these species have been identified as novel species in earlier papers (Hui et al, 2012(Hui et al, , 2013a(Hui et al, , 2013bChen et al, 2013). Amongst the insect associates, we focused on two strains of an asexual ascomycetous yeast species from the gut of the rhinoceros beetle Allomyrina dichotoma in China.…”