Fungi isolation and testing on larvae

Screening of biological activities of fungi associated with pistachio bark beetle, Chaetoptelius vestitus (Coleoptera, Curculionidae), infesting pistachio cultivations in Tunisia

AIMS

In this study, we aimed to explore the enzymatic diversity, the entomopathogenic and the antimicrobial potentialities of fungi associated with the pistachio bark beetle, Chaetoptelius vestitus.

METHODS AND RESULTS

A total of 40 isolates were screened for enzymatic diversity. Most of them, 92·5%, were able to produce at least two of the screened enzymes. Pathogenic assays performed on C. vestitus showed a high entomopathogenic activity of the isolates Ata_io_1 (A. tamarii), Fve_io_1 (F. verticillioides), Tpi_io_1 (T. pinophilus), Pal_io_1 (P. album), Pbi_io_2 (Penicillium bilaiae) and Pch_io_1 (P. chrysogenum), as based on mean mortality of C. vestitus. A screening of antimicrobial activity using well diffusion method showed that the isolates Tro_io_1 (T. pinophilus), Tat_io_1 (T. atroroseus) and Pch_io_1 (P. chrysogenum) presented the highest antibacterial activity. Furthermore, Mgu_io_1 (M. guilliermondii), Asc_io_1 (A. sclerotiorum), Ata_io_1 (A. tamarii), G. lavendula (Gla_io_1), Pva_io_1 (P. variotii), Pul_io_1 (P. ulaiense), Tat_io_1 (T. atroroseus) and Tro_io_1 (T. roseum) were active against at least two of the three tested fungal phytopathogens.

CONCLUSIONS

Fungal isolates representing entomopathogenic activity and a broad spectrum of antimicrobial activities can be considered as promising resources for biological pistachio trees protection.

SIGNIFICANCE AND IMPACT OF THE STUDY

Fungi associated with C. vestitus were investigated for detecting their potential biotechnological applications.

Dietary Phytoncide Supplementation Improved Growth Performance and Meat Quality of Finishing Pigs

We conducted this 10-wk experiment to evaluate the effects of dietary phytoncide, Korean pine extract as phytogenic feed additive (PFA), on growth performance, blood characteristics, and meat quality in finishing pigs. A total of 160 pigs ([Landrace×Yorkshire]×Duroc, body weight (BW) = 58.2±1.0 kg) were randomly allocated into 1 of 4 treatments according to their BW and sex, 10 replicate pens per treatment with 4 pigs per pen were used (2 barrows and 2 gilts). Dietary treatments were: CON, control diet; PT2, CON+0.02% PFA; PT4, CON+0.04% PFA; PT6, CON+0.06% PFA. Overall, average daily gain (ADG) was higher in PT4 (p<0.05) than in PT6, average daily feed intake (ADFI) was lower in PT6 than in CON (p<0.05). Besides ADFI decreased linearly (p<0.05) with the increased level of phytoncide and gain:feed ratio in PT4 treatment was higher (p<0.05) than CON treatment. During 5 to 10 weeks and overall, quadratic (p<0.05) effect was observed in ADG among the treatments. At the end of this experiment, pigs fed with PT4 diet had a greater (p<0.05) red blood cell concentration compared to the pigs fed CON diet. Water holding capacity increased linearly (p<0.05) with the increased level of phytoncide supplementation. Moreover, firmness, redness, yellowness, and drip loss at day 3 decreased linearly (p<0.05) with the increase in the level of phytoncide supplementation. In conclusion, inclusion of phytoncide could enhance growth performance without any adverse effects on meat quality in finishing pigs.

Influences of phytoncide supplementation on growth performance, nutrient digestibility, blood profiles, diarrhea scores and fecal microflora shedding in weaning pigs

A total of 140 weaning pigs ((Landrace×Yorkshire)×Duroc, BW = 6.47±0.86 kg) were used in a 5-wk growth trail to determine the effects of phytoncide supplementation on growth performance, nutrient apparent total tract digestibility (ATTD), blood profiles, diarrhea scores and fecal microflora shedding. Pigs were assigned randomly by BW into 5 treatments, dietary treatments were: i) NC, basal diet; ii) PC, NC+0.05% tylosin; iii) EO, NC+0.1% essential oil; iv) PP, NC+0.2% PP (phytoncide with 2% citric acid), and v) PA, NC+0.2% PA (phytoncide). Each treatment had 7 replicate pens with 4 pigs per pen. All pigs were housed in pens with a self-feeder and nipple drinker to allow ad libitum access to feed and water throughout the experimental period. During 0 to 2 wks, supplementation with essential oil and PA decreased (p<0.05) G/F compared with the other treatments. During 2 to 5 wks, supplementation with PA led to a higher (p<0.05) G/F than the other treatments. At 2 wk, ATTD of dry matter (DM) and gross energy (GE) in EO treatment were decreased (p<0.05) compared with NC treatment. Dietary PC treatment improved (p<0.05) ATTD of DM and E compared with the CON group, and PA and PP treatments showed a higher (p<0.05) ATTD of E than that in NC treatment. Pigs fed phytoncide (PA and PP) had a greater (p<0.05) ATTD of DM than those of NC and EO treatments at 5 wk. Moreover, supplementation with phytoncide elevated (p<0.05) the concentration of immunoglobulin (IgG) in blood at 2 wk. The inclusion of EO, PP and PA treatments showed a greater (p<0.05) amount of fecal Lactobacillus compared with CON group. However, no difference (p>0.05) was observed in diarrhea scores among treatments. In conclusion, phytoncide can elevate feed efficiency, nutrient digestibility, and improve the fecal Lactobacillus counts in weaning pigs. Our results indicated that the phytoncide could be used as a good antibiotics alternative in weaning pigs.