The Spatial Architecture of Bacillus subtilis Biofilms Deciphered Using a Surface-Associated Model and In Situ Imaging

The formation of multicellular communities known as biofilms is the part of bacterial life cycle in which bacteria display cooperative behaviour and differentiated phenotypes leading to specific functions. Bacillus subtilis is a Gram-positive bacterium that has served for a decade as a model to study the molecular pathways that control biofilm formation. Most of the data on B. subtilis biofilms have come from studies on the formation of pellicles at the air-liquid interface, or on the complex macrocolonies that develop on semi-solid nutritive agar. Here, using confocal laser scanning microcopy, we show that B. subtilis strains of different origins are capable of forming biofilms on immersed surfaces with dramatically protruding “beanstalk-like” structures with certain strains. Indeed, these structures can reach a height of more than 300 µm with one undomesticated strain from a medical environment. Using 14 GFP-labeled mutants previously described as affecting pellicle or complex colony formation, we have identified four genes whose inactivation significantly impeded immersed biofilm development, and one mutation triggering hyperbiofilm formation. We also identified mutations causing the three-dimensional architecture of the biofilm to be altered. Taken together, our results reveal that B. subtilis is able to form specific biofilm features on immersed surfaces, and that the development of these multicellular surface-associated communities involves regulation pathways that are common to those governing the formation of pellicle and/or complex colonies, and also some specific mechanisms. Finally, we propose the submerged surface-associated biofilm as another relevant model for the study of B. subtilis multicellular communities

The Impact of Religious Commitment on Women’s Sexual Self-Esteem

Religious commitment is associated with decreased sexual activity, poor sexual satisfaction, and sexual guilt, particularly among women. The purpose of this paper was to investigate how religious commitment is related to sexual self-esteem among women. Participants included 196 female undergraduate students, 87 % of whom identified as Christian. Participants completed the Sexual Self-Esteem Inventory for Women (SSEI-W), Religious Commitment Inventory-10, Revised Religious Fundamentalism Scale, Brief Sexual Attitudes Scale, and a measure of their perception of God’s view of sex. Results suggested that women with high religious commitment held more conservative sexual attitudes. Significant relationships between religious commitment and two subscales (moral judgment and attractiveness) of the SSEI-W revealed that women with high religious commitment were less likely to perceive sex as congruent with their moral values and simultaneously reported significantly greater confidence in their sexual attractiveness. A significant relationship between religious commitment and overall sexual self-esteem was found for women whose religion of origin was Catholicism, such that those with higher religious commitment reported lower sexual self-esteem. A hierarchical regression analysis revealed that high religious commitment and perception that God viewed sex negatively independently predicted lower sexual selfesteem, as related to moral judgment. Implications of the findings are provided