18 research outputs found
Innovation Practices in Emerging Economies: Do University Partnerships Matter?
Enterprises’ resources and capabilities determine their ability to achieve competitive advantage. In this regard, the key innovation challenges that enterprises face are liabilities associated with their age and size, and the entry barriers imposed on them. In this line, a growing number of enterprises are starting to implement innovation practices in which they employ both internal/external flows of knowledge in order to explore/exploit innovation in collaboration with commercial or scientific agents. Within this context, universities play a significant role providing fertile knowledge-intensive environments to support the exploration and exploitation of innovative and entrepreneurial ideas, especially in emerging economies, where governments have created subsidies to promote enterprise innovation through compulsory university partnerships. Based on these ideas, the purpose of this exploratory research is to provide a better understanding about the role of universities on enterprises’ innovation practices in emerging economies. More concretely, in the context of Mexico, we explored the enterprises’ motivations to collaborate with universities in terms of innovation purposes (exploration and exploitation) or alternatives to access to public funds (compulsory requirement of being involved in a university partnership). Using a sample of 10,167 Mexican enterprises in the 2012 Research and Technological Development Survey collected by the Mexican National Institute of Statistics and Geography, we tested a multinomial regression model. Our results provide insights about the relevant role of universities inside enterprises’ exploratory innovation practices, as well as, in the access of R&D research subsidies
The alkaline pectate lyase PEL168 of Bacillus subtilis heterologously expressed in Pichia pastorisis more stable and efficient for degumming ramie fiber
Mitochondrial ATPase activity and membrane fluidity changes in rat liver in response to intoxication with Buckthorn (Karwinskia humboldtiana)
Testing Protein Digestibility in Red Grouper Epinephelus Morio using In Vitro and In Vivo Methods
The digestibility of pre-selected ingredients was evaluated for Epinephelus morio using pH-stat and multi-enzyme extract (stomach, intestine, and ceca). The degree of hydrolysis (DH) was tested with acid and alkaline proteases using crustacean meals, squid meal, fish protein concentrate (FPC), fish meal, dried whey, as well as canola paste (w/ or w/o phytase), soybean meal (w/ or w/o phytase), soyprotein concentrate (SPC), and wheat gluten. SPC produced DH values between 3.6-4.1%, obtained from the three different parts of the digestive tract. Canola paste produced high DH in the stomach by adding phytase to 0.8 and 2% feed. This process was repeated under alkaline conditions for DH, with 0.6-2.6% in the pyloric ceca, and 1-2.2% in the intestine. The DH from stomach with crustacean meals (shrimp meal and crab meal) ranged from 32-87%, while values for dried whey from the ceca and intestine ranged from 6-7.4%. It did not differ from crab meal with values of 4.5 and 8.7% from pyloric ceca and intestine respectively. Based on the above results, 4 diets were developed using shrimp meal, dried whey, soy protein concentrate, and canola+phytase. The DH, FAA (fish amino acid) and SDS-PAGE (analysis of protein gels) for each diet were analysed. After an in vivo test, results on juveniles fed whey protein diet (WPd) and CPd+ ranked high (95% and 92% respectively) compared with other treatments. pH-Stat provided consistent results regarding digestibility of selected protein sources. Therefore, dried whey, shrimp meal, and canola+phytase ranked first to be included in E.morio feed formulation with a pool of 55% of these components, complemented with a minimum of fish meal, FPC, grains and wheat glute
Desarrollo de una prueba de susceptibilidad de Mycobacterium tuberculosis mediante el índice de ácidos micólicos
En el presente trabajo se desarrolló un método para
determinar la susceptibilidad de Mycobacterium tuberculosis
a drogas antituberculosas determinando
niveles de ácidos micólicos por cromatografía de
líquidos de alta resolución (CLAR). Se encontró una
relación lineal entre el logaritmo de las unidades
formadoras de colonia por mililitro y el área total
correspondiente a los picos cromatográficos de ácidos
micólicos (ATAM), y se observó que es posible
detectar la inhibición del crecimiento de M. tuberculosis
por drogas antituberculosas usando CLAR.
Con estos resultados, se propuso y evaluó una prueba
rápida de susceptibilidad de M. tuberculosis a
isoniacida y rifampicina usando aislamientos clíni-
cos y un índice de ácidos micólicos (IAM). Se determinó
la susceptibilidad o resistencia a isoniacida y
rifampicina de 200 aislamientos clínicos de M. tuberculosis
por los métodos del IAM e indirecto de
proporción. Se obtuvo una concordancia entre los
dos métodos en 398 de los 400 pruebas realizadas
(99.5%). La sensibilidad del método del IAM
para isoniacida y rifampicina fue del 97.6 y 100%,
respectivamente. La especificidad y el valor predictivo
positivo fue del 100% para ambos antifímicos.
En conclusión el método de susceptibilidad del IAM
aquí descrito se puede usar para determinar rápidamente
la susceptibilidad a drogas de aislamientos
clínicos de M. tuberculosis en cinco días después
que el aislamiento clínico se incuba en presencia
o ausencia de la droga antituberculosa
Design of Thermostable Beta-Propeller Phytases with Activity over a Broad Range of pHs and Their Overproduction by Pichia pastoris▿
Thermostable phytases, which are active over broad pH ranges, may be useful as feed additives, since they can resist the temperatures used in the feed-pelleting process. We designed new beta-propeller phytases, using a structure-guided consensus approach, from a set of amino acid sequences from Bacillus phytases and engineered Pichia pastoris strains to overproduce the enzymes. The recombinant phytases were N-glycosylated, had the correct amino-terminal sequence, showed activity over a pH range of 2.5 to 9, showed a high residual activity after 10 min of heat treatment at 80°C and pH 5.5 or 7.5, and were more thermostable at pH 7.5 than a recombinant form of phytase C from Bacillus subtilis (GenBank accession no. AAC31775). A structural analysis suggested that the higher thermostability may be due to a larger number of hydrogen bonds and to the presence of P257 in a surface loop. In addition, D336 likely plays an important role in the thermostability of the phytases at pH 7.5. The recombinant phytases showed higher thermostability at pH 5.5 than at pH 7.5. This difference was likely due to a different protein total charge at pH 5.5 from that at pH 7.5. The recombinant beta-propeller phytases described here may have potential as feed additives and in the pretreatment of vegetable flours used as ingredients in animal diets
Expression of a Bacillus Phytase C Gene in Pichia pastoris and Properties of the Recombinant Enzyme▿
The cloning and expression of a native gene encoding a Bacillus subtilis phytase using Pichia pastoris as the host is described. In addition, the influence of N-glycosylation on the biochemical properties of the B. subtilis phytase, the influence of pH on the thermostability of the recombinant and native B. subtilis phytases, and the resistance of both phytases to shrimp digestive enzymes and porcine trypsin are also described. After 48 h of methanol induction in shake flasks, a selected recombinant strain produced and secreted 0.82 U/ml (71 mg/liter) recombinant phytase. This phytase was N-glycosylated, had a molecular mass of 39 kDa after N-deglycosylation, exhibited activity within a pH range of 2.5 to 9 and at temperatures of 25 to 70°C, had high residual activity (85% ± 2%) after 10 min of heat treatment at 80°C and pH 5.5 in the presence of 5 mM CaCl2, and was resistant to shrimp digestive enzymes and porcine trypsin. Although the recombinant Bacillus phytase had pH and temperature activity profiles that were similar to those of the corresponding nonglycosylated native phytase, the thermal stabilities of the recombinant and native phytases were different, although both were calcium concentration and pH dependent
Mycolic Acid Index Susceptibility Method for Mycobacterium tuberculosis
A rapid drug susceptibility test to measure the susceptibility of Mycobacterium tuberculosis to isoniazid (INH) and rifampin (RIF) using clinical isolates and a newly defined mycolic acid index (MAI) was evaluated. A total of 200 clinical isolates of M. tuberculosis were tested for susceptibility or resistance to INH and RIF by the MAI susceptibility and indirect-proportion methods. Overall, there was agreement between the two methods for 398 (99.5%) of the 400 total tests. Specifically, the sensitivity of the MAI susceptibility method for INH and RIF was 97.6 and 100%, respectively. The specificity and positive predictive value were 100% for both drugs, and the negative predictive value for INH and RIF was 98.3 and 100%, respectively. In conclusion, the MAI susceptibility method described here can be used for rapid drug susceptibility testing of M. tuberculosis clinical isolates within 5 days after clinical isolates are incubated in the presence or absence of an antituberculosis drug