Thiaminases, enzymes that cleave vitamin B1, are sporadically distributed among prokaryotes and eukaryotes. Thiaminase I enzymes catalyze the elimination of the thiazole ring moiety from thiamin through substitution of the methylene group with a nitrogenous base or sulfhydryl compound. In eukaryotic organisms, these enzymes are reported to have much higher molecular weights than their bacterial...

Ciliates are single celled eukaryotes recognized as key players in the microbial loop of aquatic ecosystems. The present study was carried out on Krka River (Croatia), a karst freshwater ecosystem characterized by tufa barriers, biomineralization and highly diverse communities. main aims were to investigate ciliate community structure biofilm (i.e. periphyton) samples collected from light- dark...

We demonstrate how a single-celled organism could undertake associative learning. Although to date only one previous study has found experimental evidence for such learning, there is no reason in principle why it should not occur. We propose a gene regulatory network that is capable of associative learning between any pre-specified set of chemical signals, in a Hebbian manner, within a single c...

Characean plants provide an excellent experimental system for electrophysiology and physiology due to: (i) very large cell size, (ii) position on phylogenetic tree near the origin of land plants and (iii) continuous spectrum from very salt sensitive to very salt tolerant species. A range of experimental techniques is described, some unique to characean plants. Application of these methods provi...

Cotton (Gossypium hirsutum) fibers are single-celled seed coat hairs that elongate up to 2mm per day during a phase of rapid growth. Recent evidence suggests this growth is orchestrated by a series of events which includes temporary closure of plasmodesmata.

The finding that a simple single-celled organism can traverse a maze near optimally provides a challenge to some current ideas in artificial intelligence. In this paper, we present a simple explanation for such behavior and a computational model based on decision trees and ant algorithmics. The behavior of simple biological organisms may provide insights into the nature and evolution of intelli...