The Photosynthetic Apparatus and Its Regulation in the Aerobic Gammaproteobacterium Congregibacter litoralis gen. nov., sp. nov

BACKGROUND: There is accumulating evidence that in some marine environments aerobic bacteriochlorophyll a-producing bacteria represent a significant part of the microbial population. The interaction of photosynthesis and carbon metabolism in these interesting bacteria is still largely unknown and requires further investigation in order to estimate their contribution to the marine carbon cycle. METHODOLOGY/PRINCIPAL FINDINGS: Here, we analyzed the structure, composition and regulation of the photosynthetic apparatus in the obligately aerobic marine gammaproteobacterium KT71(T). Photoheterotrophically grown cells were characterized by a poorly developed lamellar intracytoplasmic membrane system, a type 1 light-harvesting antenna complex and a photosynthetic reaction center associated with a tetraheme cytochrome c. The only photosynthetic pigments produced were bacteriochlorophyll a and spirilloxanthin. Under semiaerobic conditions KT71(T) cells expressing a photosynthetic apparatus showed a light-dependent increase of growth yield in the range of 1.3-2.5 fold. The expression level of the photosynthetic apparatus depended largely on the utilized substrate, the intermediary carbon metabolism and oxygen tension. In addition, pigment synthesis was strongly influenced by light, with blue light exerting the most significant effect, implicating that proteins containing a BLUF domain may be involved in regulation of the photosynthetic apparatus. Several phenotypic traits in KT71(T) could be identified that correlated with the assumed redox state of growing cells and thus could be used to monitor the cellular redox state under various incubation conditions. CONCLUSIONS/SIGNIFICANCE: In a hypothetical model that explains the regulation of the photosynthetic apparatus in strain KT71(T) we propose that the expression of photosynthesis genes depends on the cellular redox state and is maximal under conditions that allow a balanced membrane redox state. So far, bacteria capable of an obligately aerobic, photosynthetic metabolism constitute a unique phenotype within the class Gammaproteobacteria, so that it is justified to propose a new genus and species, Congregibacter litoralis gen. nov, sp. nov., represented by the type strain KT71(T) ( = DSM 17192(T) = NBRC 104960(T))

The impact of financial incentives on physician empathy: a study from the perspective of patients with private and statutory health insurance.

OBJECTIVE: We hypothesized that patients' ratings of physician empathy (PE) would be higher among those with private health insurance (PHI, referring to financial incentive) than among patients with statutory health insurance (SHI). METHODS: A postal survey was administered to 710 cancer patients. PE was assessed using the consultation- and- Relational-Empathy measure. T-tests were conducted to analyse whether PHI and SHI-patients differ in their ratings of PE and variables relating to contact time with the physician. Structural-equation-modelling (SEM) verified mediating effects. RESULTS: PHI-patients rated physician empathy higher. SEM revealed that PHI-status has a strong significant effect on frequency of talking with the physician, which has a strong significant effect (1) on PE and (2) has a moderate effect on patients' perception of medical staff stress, thereby also affecting patients' ratings of PE. CONCLUSIONS: Our findings suggest that PHI-status is one necessary precondition for physicians spending more time with the patient. Spending more time with the PHI-patient has two major effects: it results in a more positive perception of PE and positively impacts PHI-patients' perception of medical staff stress, which in turn, again influences PE. PRACTICAL IMPLICATIONS: Health policy should discuss these findings in terms of equality in receiving high-quality care. (aut. ref.