Zoltán Naár

Selective feeding of collembolan species Tomocerus longicornis (Müll.) and Orchesella cincta (L.) on moss inhabiting fungi

Summary The composition of intestine content of two Collembolan species, Tomocerus longicornis (Mull.) and Orchesella cincta (L.) collected from Tortella tortuosa (Hedw.) Limp. moss samples, was recorded at two sites. The intestine content consisted of detritus (55 and 63%), moss particles (20 and 33%) and fungal propagules (10 and 24%), respectively. The culturable fungi was isolated and identified to reveal the selective feeding of collembolans on moss inhabiting fungi. The rate of some fungi in the intestine content markedly differed from that observed on moss. The preference of collembolans for particular fungi varied both by the insect species and the collection site.

Comparison and evaluation of molecular methods used for identification and discrimination of lactic acid bacteria

BACKGROUND Lactobacillus and Bifidobacterium strains are present in a great variety of habitats, including fermented products, probiotic concoctions and the human colon. Some species are so closely related that it is difficult to distinguish them by microbiological techniques. Nevertheless, discrimination of isolates is an important issue in respect of application, and molecular methods such as restriction fragment length polymorphism (RFLP), random amplification of polymorphic DNA (RAPD) or species-specific polymerase chain reaction (PCR) might help in resolving this problem. In this study, PCR, RFLP and sequencing were applied to identify lactobacilli and bifidobacteria originating from various sources and the DSMZ strain collection. RESULTS The microbiological composition of foods was analysed by molecular methods. Using species-specific PCR primers, three restriction enzymes (AluI, HhaI and RsaI) and sequencing, three Bifidobacterium and six Lactobacillus reference strains could be distinguished and four additional lactobacilli of food origin were identified. CONCLUSION A combination of three molecular methods resulted in successful discrimination of nine reference strains and four isolates of food origin. Since these methods are not always accurate owing to their high genetic homogeneity, it is advisable to use more than one method for the identification of L. casei and closely related species.

Growth Response of Trichoderma Species to Organic Solvents

The growth response of 25 Trichoderma strains to 26 alkanols and 7 other organic solvents was examined in vitro. The sensitivity of strains considerably varied depending on their taxonomic position, thus the strains of Longibrachiatum section proved to be more tolerant than those of Pachybasium and Trichoderma sections.

Evaluation of high‐resolution melting and other molecular methods in discrimination of Lactobacillus isolates

Fermented and probiotic products are mainly based on the activity of diverse Lactobacillus species. Distinguishing of these species, especially the closely related ones might be problematic. Our aim was to compare and evaluate molecular methods that have the potential of discrimination and might serve as alternatives of traditional microbiological techniques.