No abstract available

[en] Vitamin B12 deficiency and depletion are common world-wide, particularly in populations that consume low amounts of animal source foods. WHO and the Food Fortification Initiative recommend that wheat flour be fortified with vitamin B12 in regions where intake of B12 is low. The purpose of this pilot study in five participants was to determine if fortification of flour with B12 produced a bread product with intact B12 still present and to determine if healthy elderly absorb sufficient B12 from bread fortified in this manner. High-purity crystalline ¹⁴C-B12 was dissolved in water and added to flour (2 µg B12/100 g flour) in a bread maker and made into rolls (average 1.17 kBq (31.5 nCi) ¹⁴C-B12 in a total of 0.8 µg B12 per roll). Excess ¹⁴C first appeared in plasma 4 h after ingestion of the ¹⁴C fortified bread and plasma levels returned almost to background by 72 h. Measurement of ¹⁴C in plasma verified that the dose was absorbed into the systemic circulation. The cumulative % dose recovered in urine was 4.8–37.0% (mean = 20.1%). Most of the ¹⁴C label in the stool appeared by day 4, and the cumulative % dose recovered in stool was 24.5–43.0% (mean = 31.8%). Bioavailability among the 5 participants, calculated by subtracting the sum of urinary and fecal ¹⁴C excretion from the administered dose, was 28.4–63.7% (mean = 48.0%). This study showed that when B12 is added as a fortificant to flour it survives the fermentation and baking processes, and retains ∼50% bioavailability when fed in small doses to healthy subjects. The Recommended Dietary Allowance of B12 for adults is 2.4 µg/d. This recommendation assumes that usual bioavailability of low doses of the vitamin in the crystalline form is 60%, while for the same amount in foods such as meat and fish it is 50%. Our pilot study shows that B12 added to bread as a fortificant in flour was absorbed as well as it is from endogenous food sources such as meat and fish.

[en] This paper presents a new control strategy which unifies the direct and indirect multi-scale control schemes via a double-loop control structure. This unified control strategy is proposed for controlling a class of highly nonminimum-phase processes having both integrating and unstable modes. This type of systems is often encountered in fed-batch fermentation processes which are very difficult to stabilize via most of the existing well-established control strategies. A systematic design procedure is provided where its applicability is demonstrated via a numerical example. (paper)

No abstract available

[en] Highlights: • As digestion prolonged, C:N ratio decreased, while C:P and N:P increased. • Microbial diversity strongly related to process properties and C:N:P ratios. • Both archaeal and bacterial dominant order significantly responded to C:N:P ratios. • Process variables explained 94.1% (archaea) and 96.6% (bacteria) of total variation. -- Abstract: Ecological stoichiometry (C:N:P ratios) has been widely used to indicated the complicated microbial ecology system and microbial community, however, limited researches have been done in the anaerobic digestion process. In this study, different responses of microbial community to C:N:P stoichiometry were investigated. Results showed that bacterial diversity were higher than archaea; Beta diversity was decreased then remained stable and strongly correlated to C:N:P ratios, while it was not significant for alpha diversity. Furthermore, considering the archaeal dominant order, Methanomicrobiales showed no significant correlation with C:N:P stoichiometric ratios, but closely related to C, Methanosarcinales was positively influenced by C:N ratio, and Methanobacteriales was significantly and negatively impacted by N:P ratio. For bacteria, Clostridiales and Sphaerochaetales closely and positively related to N, Bacteroidales significantly and negatively related to P, but positively to C:N ratio, and Spirochaetales positively related to C. Moreover, changes of microbial taxa were significantly correlated with all considered process variables, which explained 94.1% and 96.6% of total variation in archaea and bacteria taxa, respectively. It is worthy note that these results could be used to predict the process performance and indicate the complicated microbial community by using the simple C:N, C:P and N:P ratios.

[en] Polyhydroxyalkanoates (PHAs) have been produced by various bacteria as natural polymers stored in bacterial cells as a source of carbon and energy. They are currently preferred biomaterials for use in many industrial fields instead of conventional non-degradable plastics. Due to their unique properties they can reduce pollution caused by the increasing global polymer demand. Pseudomonas species have been chosen as PHAs producers in many recent studies. Being metabolically versatile and possessing a remarkable tolerance to a wide range of carbon sources, these bacteria have become an efficient cell factory for PHAs production. Currently, attention is focused on the design of Pseudomonas strains to increase their ability to accumulate PHAs in the cell and modifying their biosynthetic pathways to obtain strains with modified compositions and improved properties. This article discusses the current state of knowledge of polyhydroxyalkanoates synthesized by Pseudomonas species which are industrially important microorganisms. This review provides an overview of recent trends towards PHA production, focusing on the utilization of low-cost carbon sources, fermentation strategies, PHAs properties and their uses as valuable bioproducts.

[en] Olive pomace, which is considered as one of the worst agro-industrial wastes in Mediterranean countries was tested for bioactive compounds production through the solid state fermentation of Kluyveromyces marxianus. Because they present potent biological activities, phenolic compounds from both unfermented and fermented pomace were extracted with simultaneous evaluation of their antioxidant and anticancer activities. Conditions for optimum total phenolic recovery with maximum antioxidant activity were optimized using methanol as the extracting solvent with a sample to solvent ratio of 1:10 at 50 °C for 2 hours. The in-vitro anticancer activity of both extracts was assessed against different human cancer cell lines. The results revealed that both extracts exerted anticancer effects close to the value of doxorubicin drug against liver HepG2 and breast MCF-7 cell lines, and moderate activity against prostate PC3 and colon HCT116 cell lines. Nevertheless, the fermented extract was more potent than the unfermented one. No effect against lung A549, cervix Hela cancer cell lines or normal HFB4 cells was observed for both extracts. A GC/MS analysis was carried out to determine the compounds responsible for antioxidant and anticancer activities. The results showed the presence of methyl palmitate, methyl oleate, and ethyl oleate in the methanolic extract of unfermented olive pomace, while that of the fermented one showed the production of carvacrol, thymol, eugenol, caryophyllene oxide and methyl isopalmitate.

[en] Highlights: • A specious relevance between theory and practice has always been argued. • AD approach of straw based on classical theory has been challenged. • Optimum temperature of AD deserves further exploration and updating. • A multi-stage operation strategy based on compositions is a potential approach. Anaerobic digestion (AD) of straw is a highly complex and dynamic process. The temperature range of mesophilic (30–40 °C) and thermophilic (50–65 °C) are usually recommended in textbook notion. The two-phase strategy is usually applied based on the classical theory, including acidification-phase and methanation-phase. However, both the optimized temperature parameter and the enhanced multi-phase strategy solely focus on the local AD process. A specious relevance between theory and practice during AD process of straw has always been argued. Classical AD theory was not necessarily the sufficient approach to guide the anaerobic biological transformation of straw. More profound investigations of optimum temperature are still needed, uniquely synergistic mechanisms of functional microorganisms, as well as process stability, should be taken into account. Besides, additional research should focus on the matching between the physicochemical properties and process parameters/strategies choosing. A multi-stage operation strategy based on straw material composition is a potential operation approach to improve its efficiency. Furthermore, more comprehensive attention should be paid to the collaborative response mechanism by coupling substrate, temperature, and microbial in complex AD systems for straws.

[en] Introduction of the concepts of the availability (or exergy), datum level materials, and the dead state has been regarded as some of the most significant recent developments in classical thermodynamics. Not only the available energy balance but also the material and energy balances of a biological system may be established in reference to the datum level materials in the dead state or environment. In this paper these concepts are illustrated with two examples of fermentation and are shown to be useful in identifying sources of thermodynamic inefficiency, thereby leading naturally to the rational definition of thermodynamic efficiency of a biochemical process

[en] The main concern of this study is to develop a feasible and economical technique to microbially recover metals from oxide low-grade ores. Owing to the significant quantities of metals that are embodied in low - grade ores and mining residues, these are considered new sources of metals. On the other hand, they potentially endanger the environment, as the metals they contain may be released to the environment in a hazardous form. Hence, mining industries are seeking an efficient technique to handle these ores. Pyrometallurgical and hydrometallurgical techniques are either very expensive, energy intensive or have a negative impact on the environment. For these reasons, biohydrometallurgical techniques are coming into perspective. In this study, by employing Aspergillus niger, the feasibility of recovery of metals from a mining residue is shown. A. niger exhibits good potential in generating a variety of organic acids effective for metal solubilization. Organic acid effectiveness was enhanced when sulphuric acid was added to the medium. Different agricultural wastes such as potato peels were tested. In addition to this, different auxiliary processes were tried in order to either elevate the efficiency or reduce costs. Finally, maximum solubilization of 68%, 46% and 34% were achieved for copper, zinc and nickel, respectively. Also iron codissolution was minimized as only 7% removal occurred. (author)