Lipid Composition Analysis Reveals Mechanisms of Ethanol Tolerance in the Model Yeast Saccharomyces cerevisiae.

Saccharomyces cerevisiae is an important unicellular yeast species within the biotechnological and the food and beverage industries. A significant application of this species is the production of ethanol, where concentrations are limited by cellular toxicity, often at the level of the cell membrane. Here, we characterize 61 S. cerevisiae strains for ethanol tolerance and further analyze five representatives with various ethanol tolerances. The most tolerant strain, AJ4, was dominant in coculture at 0 and 10% ethanol. Unexpectedly, although it does not have the highest noninhibitory concentration or MIC, MY29 was the dominant strain in coculture at 6% ethanol, which may be linked to differences in its basal lipidome. Although relatively few lipidomic differences were observed between strains, a significantly higher phosphatidylethanolamine concentration was observed in the least tolerant strain, MY26, at 0 and 6% ethanol compared to the other strains that became more similar at 10%, indicating potential involvement of this lipid with ethanol sensitivity. Our findings reveal that AJ4 is best able to adapt its membrane to become more fluid in the presence of ethanol and that lipid extracts from AJ4 also form the most permeable membranes. Furthermore, MY26 is least able to modulate fluidity in response to ethanol, and membranes formed from extracted lipids are least leaky at physiological ethanol concentrations. Overall, these results reveal a potential mechanism of ethanol tolerance and suggest a limited set of membrane compositions that diverse yeast species use to achieve this. IMPORTANCE Many microbial processes are not implemented at the industrial level because the product yield is poorer and more expensive than can be achieved by chemical synthesis. It is well established that microbes show stress responses during bioprocessing, and one reason for poor product output from cell factories is production conditions that are ultimately toxic to the cells. During fermentative processes, yeast cells encounter culture media with a high sugar content, which is later transformed into high ethanol concentrations. Thus, ethanol toxicity is one of the major stresses in traditional and more recent biotechnological processes. We have performed a multilayer phenotypic and lipidomic characterization of a large number of industrial and environmental strains of Saccharomyces to identify key resistant and nonresistant isolates for future applications.

The relationship of service individualization to client functioning in programs for severely mentally ill persons.

A measure of service individualization, derived from the goals in clients' treatment plans, was developed and used to evaluate this treatment process variable for 141 severely mentally ill persons served by three psychosocial rehabilitation programs. Relatively few of the 364 goals reviewed were highly individualized. Level of service individualization was inversely related to clients' functional skills, residential independence, level of education, and a primary diagnosis of an affective disorder, but positively related to a diagnosis of schizophrenia or another psychotic disorder. The goal individualization measure differentiated both between programs and among staff members, even after controlling for differences on client variables.

Relating functional skills of severely mentally ill clients to subjective and societal benefits.

OBJECTIVE: This study explored the relationship between the functional skills of clients with severe mental disorder and the benefits to the client and society as reflected by residential and vocational status, self-efficacy, self-esteem, and life satisfaction. METHODS: Relationships between various outcome variables and the demographic and clinical characteristics and staff ratings of the functional skills of 139 clients at three psychosocial rehabilitation programs for adults with severe mental disorders were analyzed using correlational techniques. The outcome variables considered were the clients' level of independence in their residential and vocational settings and their levels of self-esteem, self-efficacy, and satisfaction with life. RESULTS: Ratings of functional skills correlated positively with clients' levels of residential and vocational independence and with self-efficacy, but were unrelated to self-esteem and life satisfaction. Age, education, work and hospitalization history, psychiatric diagnosis, and length of program membership were also related to these outcome measures. Skill level remained the strongest predictor of residential and vocational status after demographic and diagnostic factors were controlled for. CONCLUSIONS: Clients' functional skills have a strong, positive relationship with their level of residential and vocational independence, and skill level is a better predictor of benefits to clients and society than are demographic and diagnostic variables.

Children with physical handicaps and their mothers: the interrelation of social support, maternal adjustment, and child adjustment.

Examined the interrelation of maternal adjustment, mother-child interaction, and child adjustment in 29 families of children with spina bifida and without mental retardation and in 28 families of children without handicaps. A multivariate, ecological model proposed that adjustment of mother and child depends on the adaptiveness of maternal response to the stress of the physical handicap and on the ability of mothers to create an optimal caregiving environment through mother-child interaction. Analyses examining the relationships among maternal social support, maternal psychological adjustment, and child adjustment are reported. Social support was found to be related to higher maternal psychological adjustment and to higher child adjustment, and maternal psychological adjustment was related positively to child adjustment in both groups. No significant differences were found between groups in the examined relationships or in the levels of resources and adjustment. Results underscore strengths of families of children with spina bifida in their adaptation to the stress of the handicap.

Community psychology into the 1990s: capitalizing opportunity and promoting innovation.

Political and social changes during the last decade and their implications for community psychology research and practice are discussed. Shifting responsibility for social problems, economic considerations, and levels of citizen concern and involvement in community problem solution are considered stimuli for new opportunities for innovation and change. The discipline is challenged to renew efforts in the promotion of innovation and to develop and disseminate interventions that result in modification in the role relationships characterizing the ecology of social problems.

The future of schooling.

Distinction is drawn between research on learning processes among children in schools and the impact of schooling on students' academic and socioemotional development. Schooling and the learning environment are considered within an ecological/transactional framework. The research on school effectiveness and teacher effects is summarized. Interventions directed at the social regularities of the schooling environment are proposed as strategies to improve the learning environment of the school and optimize student outcomes.

Organizational control and treatment program design as dimensions of institutionalization in settings for juvenile offenders.

The relationship between organizational control and normalization in treatment program design was examined in 30 community-based settings for juvenile offenders. Although these two dimensions were hypothesized to be converging indicators of the institutionality of a setting, the findings indicated that they are only marginally related. More hierarchical models of decision making were not associated with more depersonalized, isolating programming, and involvement of residents and line staff in decision making did not covary with autonomy and personalization in programming. The results are discussed as evidence that institutionality is a multidimensional construct, and that future investigations must distinguish between organizational decision making and characteristics of treatment program design when assessing the institutional quality of residential service settings.

Stress, coping, and life change in the single-parent family.

Self-perceived competence in three roles (parent, social participant, self-supporter) was examined in relation to life satisfaction in a sample of 47 divorced, employed, single parent, middle-income women. Parenting was found to be the role of greatest perceived competence, and self-supporter the role of lowest perceived competence. Competence as a self-supporter was the strongest predictor of life satisfaction. Life satisfaction did not differ significantly between groups defined by length of time as single parents. For women separated less than 3 years, the social participant was the role of least perceived competence and the best predictor of life satisfaction. For those separated more than 3 years, the three roles were nearly equal in perceived competence, but competence as self-supporter was the best predictor of life satisfaction.