Pakistan Journal of Biological Sciences - Current Issue,

---

• Comparative Study of the Colonization of Chromolaena and Tobacco Plants by Bacteria safensis CS4 using Different Methods of Inoculation
• Preparation and Properties Nano-encapsulated Wheat Germ Oil and its Use in the Manufacture of Functional Labneh Cheese
• Comparison Between Insecticidal Activity of Lantana camara Extract and its Synthesized Nanoparticles Against Anopheline mosquitoes

Comparative Study of the Colonization of Chromolaena and Tobacco Plants by Bacteria safensis CS4 using Different Methods of Inoculation Posted: Background and Objectives: This study entails the effectiveness of colonization of bacterial endophytes following inoculation of the cells in plants. Methodology: Different methods of inoculation including seed immersion, root immersion and foliar spray were studied on Chromolaena odorata and Nicotiana tabacum for 10, 20 and 30 days. This was to ascertain the colonization ability of the endophytic strain amongst the two set of plants. The foliar parts of the plants were assessed post inoculation for the presence of the bacteria strain, followed by the growth parameters in the plant. Significant differences at p<0.05 of colonization were established by the different inoculation methods. Results: Foliar spray demonstrated the highest colonization in both Chromolaena and tobacco plants followed by root immersion. Leaf inoculation in tobacco plant demonstrated a positive colonization which is not significant. However, seed inoculation provided colonization in Chromolaena plant at 10, 20 and 30 days post inoculation at a frequency lower than that of tobacco. With root immersion in Chromolaena, there was colonization at 10 days post inoculation, no colonization at 20 days post inoculation, but colonization re-appeared at 30 days (PI). Growth index measured demonstrated a positive relationship between the inoculation of the endophyte and the growth parameters which included stem length and germination rate. Conclusion: This study, therefore, showed that the bacteria strain B. safensis CS4 can effectively be horizontally transferred into tobacco and Chromolaena plants using different methods. Foliar spraying demonstrated the optimal colonization of the strain in the plant leaves.

Preparation and Properties Nano-encapsulated Wheat Germ Oil and its Use in the Manufacture of Functional Labneh Cheese Posted: Background and Objective: There is a growing interest to develop novel versions of traditional dairy products by upgrading their health properties. The use of wheat germ oil (WGO) known by its health-promoting effects, in the fortification of dairy products such as Labneh represents a challenge. This study was aimed to prepare nano-encapsulated WGO and to develop Labneh enriched with nano-encapsulated WGO. Materials and Methods: The WGO was encapsulated in casein micelles by pH changes and ultra-sonication. Transmission electron microscopy and laser light scattering characterized the size and shape of the prepared WGO capsules and their zeta potential was determined. The antioxidant activity and oxidative stability of encapsulated WGO were measured. Labneh was made from standardized (3% fat) milk and by replacement 50% of milk fat with free and encapsulated WGO, respectively. Labneh was analyzed for gross composition, textural parameters, colour and sensory properties during cold storage for 20 days. Results: High encapsulation efficiency (>95%) of different levels of WGO (0.3 to 1.2%) in casein micelles was obtained. The encapsulated WGO had a spherical shape and nano sizes. The particle sizes increased with the increase of the encapsulated level of WGO. The encapsulated WGO retained high DPPH scavenging activity and exhibited high oxidative stability. Labneh made with encapsulated WGO had composition and quality comparable to the control. Conclusion: Functional Labneh of acceptable quality and high antioxidant activity could be prepared by replacement of 50% of milk fat with encapsulated WGO.

Comparison Between Insecticidal Activity of Lantana camara Extract and its Synthesized Nanoparticles Against Anopheline mosquitoes Posted: Background and Objective: Malaria is still a severe health problem especially in developing countries which occur and young children are the most affected. The present study was designed to compare the insecticidal potential of Lantana camara leaves extract alone and its synthesized nanoparticles against Anopheles multicolor. Materials and Methods: Copper nanoparticles CuNPs were synthesized by green bio-reduction method using aqueous extract of leaves of Lantana camara plant. The CuNPs formation was confirmed by ultraviolet visible spectrophotometer (UV-VIS) and Transitional Electron Microscopy (TEM). The application of L. camara extract and its synthesized CuNPs on different stages of A. multicolor were adopted. Results: The biosynthesized CuNPs were spherical with the average sizes of 11-17.8 nm. The highest insecticidal effect (100% of larval mortality) achieved at high dose (140 ppm) of L. camara leaves extract alone comparing with that occur at low dose (20 ppm) of CuNPs synthesized L. camara leaves. The LC50 and LC90 for the 4 instar larvae were 63.5 and 119.9 ppm for plant extract alone compared to 12.6 and 18.4 ppm for CuNPs preparation. Conclusion: So, this study proved that CuNPs preparation of L. camara leaves is highly efficient compared to the plant extract alone and more economic as less quantities were used. Also, awareness against invasion of Anopheles mosquito vectors with effective preventive measures to protect from malaria infection.