Non-Conventional Yeasts Whole Cells as Efficient Biocatalysts for the Production of Flavors and Fragrances

The rising consumer requests for natural flavors and fragrances have generated great interest in the aroma industry to seek new methods to obtain fragrance and flavor compounds naturally. An alternative and attractive route for these compounds is based on bio-transformations. In this review, the application of biocatalysis by Non Conventional Yeasts (NCYs) whole cells for the production of flavor and fragrances is illustrated by a discussion of the production of different class of compounds, namely Aldehydes, Ketones and related compounds, Alcohols, Lactones, Terpenes and Terpenoids, Alkenes, and Phenols

Study of Holtermanniella wattica, Leucosporidium creatinivorum, Naganishia adeliensis, Solicoccozyma aeria, and Solicoccozyma terricola for their lipogenic aptitude from different carbon sources

Background The ability of some microorganisms to accumulate lipids is well known; however, only recently the number of studies on microbial lipid biosynthesis for obtaining oleochemical products, namely biofuels and some building blocks for chemistry, is rapidly and spectacularly increased. Since 1990s, some oleaginous yeasts were studied for their ability to accumulate lipids up to 60\u201370% of their dry weight. Due to the vast array of engineering techniques currently available, the recombinant DNA technology was the main approach followed so far for obtaining lipid-overproducing yeasts, mainly belonging to the Yarrowia lipolytica. However, an alternative approach can be offered by worldwide diversity as source of novel oleaginous yeasts. Lipogenic aptitude of a number of yeast strains has been reviewed, but many of these studies utilized a limited number of species and/or different culture conditions that make impossible the comparison of different results. Accordingly, the lipogenic aptitude inside the yeast world is still far from being fully explored, and finding new oleaginous yeast species can acquire a strategic importance. Results Holtermanniella wattica, Leucosporidium creatinivorum, Naganishia adeliensis, Solicoccozyma aeria, and Solicoccozyma terricola strains were selected as a result of a large-scale screening on 706 yeasts (both Ascomycota and Basidiomycota). Lipid yields and fatty acid profiles of selected strains were evaluated at 20 and 25 \ub0C on glucose, and on glycerol, xylose, galactose, sucrose, maltose, and cellobiose. A variable fatty acid profile was observed in dependence of both temperature and different carbon sources. On the whole, L. creatinivorum exhibited the highest performances: total lipid yield (YL) >7 g/l on glucose and glycerol, % of intracellular lipids on cell biomass (YL/DW) >70% at 20 \ub0C on glucose, lipid coefficient (YL/Glu) around 20% on glucose, and daily productivity (YL/d) on glucose and sucrose >1.6 g/(l*d). Conclusions This study provides some meaningful information about the lipogenic ability of some yeast species. Variable lipid yields and fatty acid profiles were observed in dependence of both temperature and different carbon sources. L. creatinivorum exhibited the highest lipogenic performances

Yeast and yeast-like diversity in the southernmost glacier of Europe (Calderone Glacier, Apennines, Italy)

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Observational study on Lifestyle Behaviours and Nutrition in individuals undergoing genetic counseling for breast or colorectal cancer risk

BACKGROUND: Healthy lifestyles are associated with cancer risk reduction. Individuals with hereditary cancer syndromes may be motivated to adopt health-protective behaviours. OBJECTIVE:  This study explored lifestyle behaviours associated to cancer risk reduction among individuals undergoing breast or colorectal cancer familial risk assessment. METHOD: A cross-sectional survey was performed through a self-administered questionnaire, including: the Italian validated Medi-Lite and the International Physical Activity validated questionnaires (to assess adherence to the Mediterranean Diet and Physical activity), items on cancer risk perception, lifestyle and surveillance. RESULTS: Forty-two women and eight men (age: 19-80 years) responded; 19 were affected by breast cancer, four by colorectal cancer, 27 were unaffected but had a family history of breast (n=23) or colorectal (n=4) cancer. The majority perceived their general lifestyle as moderately healthy. However, 16 (32%) were current or former smokers, 37 (74%) drank alcohol and 18 (36%) were overweight or obese; 21 (42%) showed low adherence to Mediterranean diet and seven (14%) reported low exercise. Adherence to Mediterranean diet was generally low (Medi-Lite score: 8.8±2.6): a low adherence was significantly more frequent in participants of lower education level (67%), compared to those with high education level (17%; p=0.044). Participants at higher cancer risk were significantly more likely to smoke: 63% of those at high risk, 40% at intermediate risk and 14% at standard risk were current or former smokers (p <0.05). CONCLUSION: These findings suggest a need for raising awareness on the role of the lifestyle in cancer risk modulation among individuals at increased familial risk

Molecular characterization of Prototheca strains isolated from Italian dairy herds.

One hundred sixty-one Prototheca spp. strains isolated from composite milk and barn-surrounding environmental samples (bedding, feces, drinking, or washing water, surface swabs) of 24 Italian dairy herds were characterized by genotype-specific PCR analysis. Overall, 97.2% of strains isolated from composite milk samples were characterized as Prototheca zopfii genotype 2, confirming its role as the main mastitis pathogen, whereas Prototheca blaschkeae was only sporadically isolated (2.8%). Regarding environmental sampling, 84.9% of isolates belonged to P. zopfii genotype 2, 13.2% to P. blaschkeae, and 1.9% to P. zopfii genotype 1. The data herein contradict previous hypotheses about the supposed exclusive role of P. zopfii genotype 2 as the causative agent of protothecal mastitis and, on the contrary, confirm the hypothesis that such pathology could be caused by P. blaschkeae in a few instances

A comparative study of the in vitro activity of iodopropynyl butylcarbamate and amphotericin B against Prototheca spp. isolates from European dairy herds.

ABSTRACT The objective of this study was to assess the in vitro effect of iodopropynyl butylcarbamate (IPBC) and amphotericin B (AMB) on Prototheca zopfii genotype 2 and Prototheca blaschkeae isolates recovered from dairy herds of Belgium, France, Italy, Germany, and Poland. The combination of IPBC with AMB on Prototheca isolates and toxicity of IPBC to the bovine mammary epithelial cells were also evaluated. The in vitro activity of IPBC and AMB against 96 isolates of P. zopfii genotype 2 and 42 isolates of P. blaschkeae was performed. Minimum inhibitory concentrations (MIC) and minimum algicidal concentrations (MAC) of IPBC and AMB were determined. To determine any synergistic, additive, or antagonistic effect of the combination of IPBC and AMB, 2-dimensional checkerboard combination tests were also performed to calculate fractional inhibitory concentrations. Cytotoxicity analysis of IPBC to the bovine mammary epithelial cell line was performed using a 3-(4,5-dimethyl-2-thiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The MIC for 50 and 90% of isolates (MIC 50 and MIC 90 , respectively) for IPBC were 4 and 8 mg/L versus 0.5 and 1 mg/L for AMB, respectively. The MIC profiles differed between P. zopfii genotype 2 and P. blaschkeae , with the latter species being more susceptible to both compounds. The MIC 50 and MIC 90 of IPBC were 4 and 8 mg/L for P. zopfii genotype 2 and 1 and 2 mg/L for P. blaschkeae , respectively. The MIC 50 and MIC 90 of AMB were both 1 mg/L for P. zopfii genotype 2 and 0.25 and 1 mg/L for P. blaschkeae , respectively. Both IPBC and AMB exhibited the ability to kill Prototheca spp. The MAC for 90% of isolates of IPBC was twice the MIC 90 , whereas an 8-fold increase of the MIC 90 was algicidal in the case of AMB. Overall, the combined use of IPBC and AMB exhibited an increased algicidal effect, albeit the fractional inhibitory concentration index showed synergistic activity only against 3 P. zopfii genotype 2 isolates. For all the remaining isolates (87.5%), this combination produced only an additive effect. The MTT assay results showed both IPBC and AMB, at the concentrations employed in the study, to be nontoxic to the epithelial mammary gland cells (cell viability >90%). Notably, only IPBC at the highest concentration (i.e., 8 mg/L) exerted a slight cytotoxic effect on the cell line tested (mean cell viability: 88.54 ± 3.88 and 90.66 ± 3.0, after 2 and 4 h of MTT treatment, respectively). The anti- Prototheca activity of IPBC was here demonstrated for the first time. In addition, the combined use of IPBC with AMB enhanced each other's effect, creating an additive rather than synergistic interaction. Both agents, used at concentrations corresponding to MIC values against Prototheca spp., showed no toxic effect for the mammary epithelial cells. In conclusion, IPBC, used either alone or in combination with AMB, can be considered a promising option in the treatment armamentarium for protothecal mastitis in dairy cows

The hidden network of biocrust successional stages in the High Arctic: Revealing abiotic and biotic factors shaping microbial and metazoan communities

Despite the important role that biocrust communities play in maintaining ecosystem structure and functioning in deglaciated barren soil, few studies have been conducted on the dynamics of biotic communities and the impact of physicochemical characteristics in shaping the different successional stages. In this study an integrated approach encompassing physicochemical parameters and molecular taxonomy was used for identifying the indicator taxa and the presence of intra- and inter-kingdom interactions in five different crust/biocrust successional stages: i) physical crust, ii) cyanobacteria-dominated biocrust, iii) cyanobacteria/ moss-dominated biocrust, iv) moss-dominated biocrust and v) bryophyte carpet

Implications of nurse species in mixed forest plantations management on soil fungal community diversity

Mixed plantations provide numerous benefits in terms of ecosystem and socioeconomic services, as well as on soil chemical and biological parameters; thus, a forest management allowing to recover overexploited soils is highly recommended. Although nurse species may deeply affect soil properties, few studies are present in literature assessing their role. A study site characterized by a mixed plantation established on a former agricultural area was selected in order to evaluate the impact of a specific forest management on marginal soils, with a special emphasis on the role of nurse species. The intercropping systems investigated feature two economically important species, Populus alba and Juglans regia, along with one of following nurse trees, Alnus cordata, Elaeagnus umbellata (both N-fixing species), and Corylus avellana. Each stand was replicated three times, and an adjacent agricultural field was included for comparison. Methodologically, topsoils (0–10 cm of depth) were sampled and several chemical and biological parameters determined. Fungal taxa, as well as fungal ecological guilds and their functional roles, were identified by means of metabarcoding analysis. Ectomycorrhizal fungi dominated tree consociations (53.5 %), while non-mycorrhizal saprophytes dominated the arable, control soil (5.3 %). Two-Block Partial Least Squares showed differences both among tree consociations, where the presence of the Alnus cordata resulted in the highest concentration of organic carbon (19.10±1.8 mg g-1), total nitrogen (1.78±0.1 mg g-1), lignin (11.25±1.1 mg g-1), cellulose (1.54±0.2 mg g-1), and bioavailable phosphorus (8.99±1.2 mg kg-1), as well as fluorescein diacetate hydrolase enzyme activity, and between tree consociation and the arable land. Thus, the utilization of Alnus cordata as a nurse species seems to be the best solution for a forest management capable of improving soil chemical and biological quality, providing a viable strategy for the restoration of marginal soils, particularly in a climate change scenario