Distribution of Recent ostracods in inland waters of Sicily (Southern Italy)

From 2003 to 2005, freshwater ostracods were sampled in 67 water bodies of mainland Sicily (Provinces of Agrigento, Caltanisetta, Catania, Enna, Palermo, Messina, Ragusa, Siracusa and Trapani) located from sea level up to 1300 m a.s.l. This survey took into account streams, springs, wells, but especially temporary and ephemeral habitats (e.g., flooded meadows, temporary ponds). The aim of this research was to give the first comprehensive picture of the regional ostracod fauna and establish relationships between the distribution of ostracod species and some habitat features. Altogether, 21 ostracod taxa belonging to five families (Candonidae, Ilyocyprididae, Cyprididae, Notodromadidae, and Limnocytheridae) were identified. A maximum of four species was found in a single sample. The most frequent species was Heterocypris incongruens, followed by Eucypris virens. The following ten taxa have been found only once: Candona lindneri, Ilyocypris decipiens, Notodromas persica, Trajancypris clavata, Herpetocypris brevicaudata, Heterocypris salina, Cypridopsis cf. elongata, Cypridopsis vidua, Potamocypris cf. villosa, and Limnocythere inopinata. The faunal assemblage of Sicily is compared with the known ostracod distribution in some Mediterranean areas

Effect of Glucose and Inactivated Yeast Additions on the Fermentation Performances of Lactiplantibacillus pentosus OM13 during the Production of Nocellara del Belice Table Olives

The use of selected strains of lactic acid bacteria is necessary to produce fermented table olives with high hygiene and quality standards at the industrial level. A current tendency is the use of fermentation adjuvants (nutrients and activators) that can satisfy the nutritional needs of starter strains. In this study, five experimental protocols, different for nutrient and activator presence and addition of Lactiplantibacillus pentosus OM13 in freeze-dried form and after acclimatisation, were tested with the aim of improving the fermentation performances of the commercial starter. The trial inoculated with the starter strain acclimatised in the presence of nutrients and activator showed the most rapid acidification during the first phase of fermentation (third to ninth day), registering a pH loss of 3.40 units. The addition of adjuvants positively influences starter dominance (>89%) and rapid colonisation (>7 Log CFU/mL from third d) by indirectly limiting the presence of undesirable microorganisms. The analysis of volatile organic compounds revealed the presence of 32 chemicals distributed differently in each trial. Sensory evaluation showed that table olives produced with the different treatments were characterised by low bitterness, acidity, and absence of unpleasant odours/flavours. Control production showed slower acidification kinetics and lower sensory pleasantness than the other trials

Application of technological protocols on an industrial scale to improve Seville-style table olive production in Italy and Spain

Improving the fermentation performance of starter strains used in the fermentation of table olives is a biotechnological solution of current interest to improve the quality characteristics of the final product. The aim of this study was to evaluate the use of Lactiplantibacillus pentosus OM13 as a starter culture for the fermentation of Seville-type table olives in two different production areas: Italy and Spain. The starter strain L. pentosus OM13 was inoculated into two different table olive varieties: Nocellara del Belice in Italy and Manzanilla in Spain. Lactiplantibacillus plantarum Vege-Start 60 was used as a commercial control, while an additional control pro- duction was carried out by spontaneous fermentation. The industrial productions consisted of three different protocols, differing in the type of nutrient and the presence/absence of acclimatisation of the starter strain. All trials were subjected to microbiological monitoring, evaluation of acidification dynamics and sensory analysis of the final product. After 90 days, the pH reached values below 5 in the different treatments. The LAB reached microbial loads varying between 6.5 and 8.7 log CFU/mL throughout the monitoring period. The microbial populations of spoilage and/or potential pathogenic microorganisms were variable depending on the microbial group monitored. However, after 12 days of fermentation, Enterobacteriaceae showed values below the detection limit. In contrast, a fluctuating trend was observed for yeasts, Pseudomonadaceae and Staphylococcaceae. Sensory analyses showed variable differences depending on the technological protocol used. Table olives ob- tained with L. pentosus OM13 in the presence of nutrient, activator and acclimatisation period achieved higher overall acceptability values compared to the other trials. The use of adjuvants (nutrients and activators) is a strategy used in the production of table olives fermented with L. pentosus OM13 to improve the sensory char- acteristics of table olives

Effects of the filter-feeding benthic bivalve corbicula fluminea on plankton community and water quality in aquatic ecosystems: A mesocosm study

The influence of filter-feeding bivalves on plankton communities, nutrients, and water quality in a given aquatic ecosystem is so profound that they can be considered ecosystem engineers. In a 70-day mesocosm experiment, we tested the hypothesis that Corbicula fluminea would change plankton community structure by reducing small zooplankton and large phytoplankton and improve water quality by reducing nutrients. We monitored levels of nitrogen and phosphorus, organic suspended solids (OSS), and light at the sediment surface. Within the plankton, phytoplankton biomass (as Chl a, >0.45 μm), the biomass of microphytoplankton (>20 μm), nanophytoplankton (2–20 μm), picophytoplankton (0.2–2 μm), and zooplankton were determined. Compared with the controls, C. fluminea reduced the abundance of rotifers and the biomass of phytoplankton, and picophytoplankton, thereby modifying the plankton community structure. We did not observe reductions in TN and TP concentration, but OSS concentrations were reduced, and light intensity at the sediment surface was increased as a result of the improved water transparency. Our research shows that colonization by C. fluminea may modify plankton community structure and improve water quality of eutrophic shallow lakes, shedding further light on the ecological roles of filter-feeding bivalves in aquatic ecosystems

Improving the Aromatic Profiles of Catarratto Wines: Impact of Metschnikowia pulcherrima and Glutathione-Rich Inactivated Yeasts

Catarratto is one of the most widely cultivated grape varieties in Sicily. It is an indigenous non-aromatic white grape variety. Despite its widespread use in winemaking, knowledge of the aroma and chemical and microbiological properties of Catarratto wines is quite limited. The influence of Metschnikowia pulcherrima combined with Saccharomyces cerevisiae on the aromatic expression of Catarratto wines was investigated with and without the addition of glutathione-rich inactivated yeast. The substance is a natural specific inactivated yeast with a guaranteed glutathione level used to limit oxidative processes. The aromatic profiles of the final wines were determined through analysis of the volatile organic compounds using a solid-phase microextraction technique that identified 26 aromatic compounds. The addition of M. pulcherrima in combination with the natural antioxidant undoubtedly increased the aromatic complexity of the wines. Dodecanal was exclusively detected in the wines processed with glutathione-rich inactivated yeasts. Furthermore, the presence of this natural antioxidant increased the concentration of six esters above the perception threshold. Sensory analysis was also performed with a panel of trained judges who confirmed the aromatic differences among the wines. These results suggest the suitability of glutathione-rich inactivated yeasts for determining the oxidative stability of Catarratto wines, thus preserving its aromatic compounds and colour

A novel microbiological approach to impact the aromatic composition of sour loquat beer

The growing interest in novel beer development determined the exploitation of unconventional yeasts isolated from novel ecological niches to generate unexplored sensory profiles. In recent years, there is an increasing interest in generating beers brewed with the addition of fruits. For the first time, Lachancea thermotolerans MNF105 and Saccharomyces cerevisiae MN113 isolated from manna, were tested as starter cultures to process loquat beer to improve the sensory profile. Innovatively, the yeast species L. thermotolerans was investigated for the production of sour fruit beer. Sour fruit beers produced with L. thermotolerans MNF105 were more balanced than the respective control, especially in terms of perceived acidity during sensory analysis. This could be due to the lower lactic acid production (0.49 g/L) compared to the respective control (1.74 g/L). The overall organoleptic investigation showed a preference for S. cerevisiae MN113 (TF1) isolated from manna. Experimental trials conducted with the selected strains demonstrated the absence of off-odour and off-flavour and improved aroma perception. Aldehydes and alcohols were the most abundant compounds emitted from the beers. S. cerevisiae MN113 and L. thermotolerans MNF105, manna related yeasts, showed great technological properties, representing promising starters for the production of fruit beer and sour fruit beer

Seasonal water level fluctuations: Implications for reservoir limnology and management

With the purpose of finding out whether seasonal water level fluctuations could affect water quality in a reservoir subjected to those changes, trends in environmental variables and in phytoplankton and zooplankton assemblages were analysed. The reservoir’s hydrological cycle was characterized by three regimes. The maximum level phase lasted from January to the beginning of June, the emptying phase existed between mid-June to the beginning of September and the minimum level phase lasted from mid-September to the beginning of the first autumn/winter rain events. The highest values of total phosphorus, soluble reactive phosphorus, nitrate, water colour and chlorophyll a were found during the minimum level phase. The phytoplankton assemblage was dominated by taxa typical of meso-eutrophic environments during the emptying and minimum level phases. However, during the maximum level phase, taxa generally found in more oligotrophic systems were observed here also. Similar to other disturbed systems, the zooplankton assemblage was dominated by Rotifera, except in summer and autumn when the cladoceran Ceriodaphnia quadrangula and/or the copepod Tropocyclops prasinus became dominant. Although those shifts seem to be related to water level variations, further research is needed to evaluate to what extent they might also be induced by other seasonal factors acting independently of water fluctuations. Based upon the obtained data, suggestions for reservoir management are proposed

Impact of two new non-conventional yeasts, Candida oleophila and Starmerella lactis-condensi, isolated from sugar-rich substrates, on Frappato wine aroma

The interest of non-Saccharomyces yeasts in wine fermentation increased constantly in last years. This study reports for the first time the enological potential of two strains Starmerella lactis-condensi MN412 and Candida oleophila YS209. In an innovative way, these strains were used in winemaking to improve floral and fruity aroma of Frappato red wine, which has not been explored. The enological performances of the two non-Saccharomyces strains were compared to a wine strain of Starmerella bacillaris, namely Cz3, previously characterized in winemaking conditions. In these three cases, the non-Saccharomyces strain was sequentially inoculated with S. cerevisiae wine strain NF213, used as control. The St. lactis-condensi MN412 was isolated from Sicilian manna, a sugar-rich matrix, extracted from Fraxinus angustifolia trees (Oleaceae). The strain C. oleophila YS209 was isolated from honey by-products. Microbiological counts showed the ability of MN412 and YS209 to maintain high counts up to 6 days of alcoholic fermentation. Regarding chemical parameters, Cz3 showed the highest glycerol production. Analysis of VOCs revealed that the trials with non-Saccharomyces yeasts were characterized by a higher concentration of esters that contributed positively to the fruity aroma of the wines. The sensory analysis confirmed that the use of MN412 and YS209 impacted positively the final wines in terms of fruity and floral intensity, respectively, while did not generate sensory defects. In conclusion, non-conventional yeasts represent strategy to improve floral-fruity freshness of wine aroma and sugar-rich matrices such as manna ash and honey might represent novel ecological niches as source of potential oenological yeast