As a means to improve carbon uptake in the cyanobacterium Synechocystis sp. strain PCC6803, we engineered strains to contain additional inducible copies of the endogenous bicarbonate transporter BicA, an essential component of the CO2-concentrating mechanism in cyanobacteria. When cultured under atmospheric CO2 pressure, the strain expressing extra BicA transporters (BicA(+) strain) grew almost twice as fast and accumulated almost twice as much biomass as the control strain. When enriched with 0.5% or 5% CO2, the BicA(+) strain grew slower than the control but still showed a superior biomass production. Introducing a point mutation in the large C-terminal cytosolic domain of the inserted BicA, at a site implicated in allosteric regulation of transport activity, resulted in a strain (BicA(+)(T485G) strain) that exhibited pronounced cell aggregation and failed to grow at 5% CO2. However, the bicarbonate uptake capacity of the induced BicA(+)(T485G) was twice higher than for the wild-type strain. Metabolic analyses, including phenotyping by synchrotron-radiation Fourier transform Infrared spectromicroscopy, scanning electron microscopy, and lectin staining, suggest that the excess assimilated carbon in BicA(+) and BicA(+)(T485G) cells was directed into production of saccharide-rich exopolymeric substances. We propose that the increased capacity for CO2 uptake in the BicA(+) strain can be capitalized on by re-directing carbon flux from exopolymeric substances to other end products such as fuels or high-value chemicals.

No abstract

Hemodialysis (HD) patients face a common problem of malnutrition due to poor appetite. This study aims to verify the appetite alteration model for malnutrition in HD patients through quantitative data and the International Classification of Functioning, Disability, and Health (ICF) framework. This study uses the Mixed Method-Grounded Theory (MM-GT) method to explore various factors and processes affecting malnutrition in HD patients, create a suitable treatment model, and validate it systematically by combining qualitative and quantitative data and procedures. The demographics and medical histories of 14 patients were collected. Based on the theory, the research design is based on expansion and confirmation sequence. The usefulness and cut-off points of the creatinine index (CI) guidelines for malnutrition in HD patients were linked to significant categories of GT and the domain of ICF. The retrospective CIs for 3 months revealed patients with 3 different levels of appetite status at nutrition assessment and 2 levels of uremic removal. In the same way, different levels of dry mouth, functional support, self-efficacy, and self-management were analyzed. Poor appetite, degree of dryness, and degree of taste change negatively affected CI, while self-management, uremic removal, functional support, and self-efficacy positively affected CI. This study identified and validated the essential components of appetite alteration in HD patients. These MM-GT methods can guide the selection of outcome measurements and facilitate the perspective of a holistic approach to self-management and intervention.

PurposeThis study analyzed the factors affecting visual attention toward sugar-reduction information (SRI) on sugar-reduced beverages (SRBs) and identified the most optimal SRI type and location using eye-tracking. The eye-tracking results were compared with those of a self-reported questionnaire.Design/methodology/approachAn eye-tracking experiment was conducted on 50 Korean people in their 20s and 30s to analyze implicit responses. Subsequently, a self-reported questionnaire was administered to analyze explicit responses, facilitating the investigation of perceptions, attitudes, preferences, intentions to purchase SRBs, and preferred SRI types and positions.FindingsThe results were as follows. First, personal trait-, state-, and product-related factors were found to affect eye movement in relation to SRI. Second, eye-tracking revealed that SRI types and locations that drew long-lasting fixation and attracted considerable attention were similar to those preferred in the self-reported questionnaire. Therefore, to efficiently convey information on SRBs, SRI should be combined with a graphic, and not merely a word, and placed in the upper-right corner, exhibiting consistency with the results of two previous experiments.Originality/valueThis study specifically focused on considering personal and product-related traits while conducting an eye-tracking experiment to investigate the factors that attract consumers' attention. Furthermore, this study is the first to investigate the use of SRI labels to promote SRB selection. What is significant is that both explicit and implicit responses were assessed and compared via a self-reported survey and eye-tracking experiments for various SRB categories.