Lactococcus taiwanensis sp. nov., a lactic acid bacterium isolated from fresh cummingcordia.

One coccal strain, designated 0905C15(T), was isolated from fresh cummingcordia, which is the main ingredient of pobuzihi (fermented cummingcordia), a traditional fermented food in Taiwan. 16S rRNA gene sequencing results showed that strain 0905C15(T) had 98.22-98.82 % sequence similarity to that of the type strains of four Lactococcus lactis subspecies (L. lactis subsp. lactis BCRC 12312(T), L. lactis subsp. cremoris BCRC 12586(T), L. lactis subsp. hordniae BCRC 80474(T) and L. lactis subsp. tructae BCRC 80475(T)). Comparison of two housekeeping genes, recA and rpoB, revealed that strain 0905C15(T) was well separated from the reference strains of the genus Lactococcus. DNA-DNA hybridization studies indicated that strain 0905C15(T) had low DNA relatedness to the four Lactococcus lactis subspecies (9.7-15.24 %). The DNA G+C content of strain 0905C15(T) was 39.6 mol %. Based on the evidence, strain 0905C15(T) represents a novel species of the genus Lactococcus, for which the name Lactococcus taiwanensis sp. nov. is proposed. The type strain is 0905C15(T) ( = NBRC 109049(T) = BCRC 80460(T)).

Endophytic fungi reduce leaf-cutting ant damage to seedlings.

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (E(high)) or low (E(low)) densities of endophytes. The E(high) seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the E(low) treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from E(low) relative to E(high) seedlings and had a tendency to recruit more ants to E(low) plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities.

Specific, non-nutritional association between an ascomycete fungus and Allomerus plant-ants.

Ant-fungus associations are well known from attine ants, whose nutrition is based on a symbiosis with basidiomycete fungi. Otherwise, only a few non-nutritional ant-fungus associations have been recorded to date. Here we focus on one of these associations involving Allomerus plant-ants that build galleried structures on their myrmecophytic hosts in order to ambush prey. We show that this association is not opportunistic because the ants select from a monophyletic group of closely related fungal haplotypes of an ascomycete species from the order Chaetothyriales that consistently grows on and has been isolated from the galleries. Both the ants' behaviour and an analysis of the genetic population structure of the ants and the fungus argue for host specificity in this interaction. The ants' behaviour reveals a major investment in manipulating, growing and cleaning the fungus. A molecular analysis of the fungus demonstrates the widespread occurrence of one haplotype and many other haplotypes with a lower occurrence, as well as significant variation in the presence of these fungal haplotypes between areas and ant species. Altogether, these results suggest that such an interaction might represent an as-yet undescribed type of specific association between ants and fungus in which the ants cultivate fungal mycelia to strengthen their hunting galleries.

Lactobacillus pobuzihii sp. nov., isolated from pobuzihi (fermented cummingcordia).

Twenty-one homofermentative lactic acid bacteria were isolated from fermented cummingcordia (pobuzihi), a traditional food in Taiwan. The isolates had identical 16S rRNA gene sequences that were distinct from those of other lactobacilli, and their closest neighbours in the 16S rRNA gene sequence phylogenetic tree were strains of Lactobacillus acidipiscis. Levels of DNA-DNA relatedness between representative pobuzihi isolates and strains of L. acidipiscis were 17% and below. Furthermore, the new isolates could be differentiated clearly from L. acidipiscis NBRC 102163T and NBRC 102164 in terms of acid production from L-arabinose, rhamnose, mannitol, lactose and 5-ketogluconate. It was concluded that the new isolates represent a single novel species of the genus Lactobacillus, for which the name Lactobacillus pobuzihii sp. nov. is proposed. The type strain is E100301T (=RIFY 6501T =NBRC 103219T =KCTC 13174T).