The occurrence of various amounts of 5-n-alkylresorcinols was shown in lipids extracted from 14 bacterial strains of Azotobacter chroococcum as well as from strains of Pseudomonas aureofaciens, P. chlororapsis, and P. fluorescens. The amount of alkylresorcinols found varied from 2.3 to 56.2 g/mg (dry weight) of cells in A. chroococcum and from 0.2 to 0.8 g/mg (dry weight) of cells in Pseudomonas spp. Strains of both genera produce saturated homologs with C 13 to C 27 side chains. C 19 , C 21 , and C 23 homologs are predominant in and characteristic for A. chroococum strains, the C 15 homolog is predominant in and characteristic for P. chlororapsis and P. fluorescens, and the C 17 homolog is predominant in and characteristic for P. aureofaciens. The presence of 5-n-(2-ketoalkyl)resorcinols, not previously observed, was demonstrated in lipids isolated from the cells of A. chroococum Az5.Alkylresorcinols-long-chain, odd-numbered homologs of orcinol (1,3-dihydroxy-5-methylbenzene)-were demonstrated initially only in the plant kingdom. First, their occurrence in plants from the families Anacardiaceae (Anacardium occidentale [cashew]) and Ginkgoaceae (Ginkgo biloba) was demonstrated (24). In these plants mostly unsaturated homologs of 5-n-pentadecylresorcinol were found. Later, homologs with longer side chains and their derivatives were demonstrated in various species of Gramineae, including cereals and several other plant families such as Proteaceae, Myrsinaceae, Myristicaceae, Liliaceae, and Leguminosae (1, 24; also, references therein). Reusch and Sadoff (15,16) Further experiments showed that during encystment of A. vinelandii over 70% of lipids were replaced with resorcinolic and other phenolic lipids (19). Alkylresorcinols consisted of half of these phenolic compounds. In contrast to plant sources, the alkyl chains of hitherto identified bacterial alkylresorcinols are exclusively saturated.The biological role of these compounds in bacterial organisms is not known yet. Their increasing level during encystment and alteration of cellular metabolism suggest that they are autoregulatory anabiotic compounds (3, 13).Although occurrence of resorcinolic lipids in single strains of Azotobacter and Pseudomonas spp. was indicated, there were no data concerning the abundance of these compounds in various strains from these genera. In this paper we present data indicating that the occurrence of 5-n-alkylresorcinol homologs of various chain lengths is also a characteristic feature in various Azotobacter and Pseudomonas strains and species. MATERIALS AND METHODS Microorganisms.Azotobacter strains were isolated from the organic layer of arable land collected near Wrocl ͞aw. They were identified by the method of Thompson and Skerman (20) at the Department of Agricultural Microbiology, Agricultural University at Wrocl ͞aw. There were 14 strains of A. chroococcum: Az1, Az4, Az5, Az7, Az6, Az8, Az9, Az10, Az11, Az12, Az13, Az15, Az17, and Az18. Three strains from the genus Pseudomonas were used for the study. P. aureofaciens PGS12...

Summary. Phosphonic acid analogue of forfenicine, amino(p-formylbenzyl)-phosphonic acid, was synthesized and evaluated as antibacterial agent. As indicated by disc diffusion test this compound was found to inhibit significantly the growth of Bacillus subtilis and Staphylococcus aureus and moderately the growth of Escherichia coli. Resistance of Pseudomonas fluorescens to the action of the aminophosphonate may result from the ability of the strain to degrade this compound.

To assess the immune potential of spiders, in the present study juvenile and adult females of Parasteatoda tepidariorum were exposed to Bacillus subtilis infection, injury by a nylon monofilament and a combination of both. The expression level of selected immune-related genes: defensin 1 (PtDEF1), lysozyme 1 (PtLYS1), lysozyme C (PtLYSC), lysozyme M1 (PtLYSM1), autophagy-related protein 101 (PtATG101), dynamin (PtDYN) and heat shock proteins (HSP70) (PtHSPB, PtHSPB2A, PtHSPB2B), production of lysozyme and HSP70 proteins, and hemocytes viability were measured. The obtained results indicated expression of the lysozyme, autophagy-related protein and HSP70 genes in both ontogenetic stages of P. tepidariorum. It has been also shown that the simultaneous action of mechanical and biological factors causes higher level of lysozyme and HSP70, cell apoptosis intensity and lower level of hemocytes viability than in the case of exposure to a single immunostimulant. Moreover, mature females showed stronger early immune responses compared to juveniles.