اسم ِ استفہامیہ :کم؟(کتنا)
ارشارِ ربانی ہے:
"كَمْ أَهْلَكْنَا مِنْ قَبْلِهِمْ مِنْ قَرْنٍ فَنَادَوْا وَلَاتَ حِينَ مَنَاصٍ"۔ [[1]]
" کتنی ہی امتوں کو ہم (عذاب سے) ہلاک کر چکے ہیں سو انہوں نے (ہلاکت کے وقت) بڑی ہائے پکار کی اور وہ وقت خلاصی کا نہ تھا"۔
یعنی ان کو معلوم رہنا چاہیے کہ اسی غرور وتکبر کی بدولت انبیاء اللہ سے مقابلہ ٹھان کر بہت سی جماعتیں پہلے تباہ و برباد ہو چکی ہیں وہ لوگ بھی مدتوں پیغمبروں سے لڑتے رہے۔ پھر جب برا وقت آ پڑا اور عذاب الٰہی نے چاروں طرف سے گھیر لیا تو گھبرا کر شور مچانے اور خدا کو پکارنے لگے۔ مگر اس وقت فریاد کرنے سے کیا بنتا۔ خلاصی کا موقع گزر چکا تھا، اور وقت نہیں رہا تھا کہ ان کے شوروبکاء کی طرف توجہ کی جائے۔
Islam has provided guidance in agriculture like any other field of life. Agriculture provides food and nourishment to men, animals and birds. Pakistan is an agricultural land. Out of total grass root of Pakistan economy, 80% depends upon the agriculture. Agriculture is the production of food, feed and fiber by the systematic harvesting of plants and animals. The history of agriculture is a central element of human history. The article deals with the study of Muslims’ contribution to agriculture especially the Prophetic and four caliphs’ time. The Prophet r initiated the development of a sophisticated system of irrigation, and the Caliphs Hazrat Umar R. A and Hazrat Uthman R. A suggested revolution in agricultural reforms. The Islamic rules on land ownership and labor rights, alongside the recognition of private ownership and introduction of share cropping created by incentives to engage in agriculture. The present system prevailing in Pakistan has several short comings. Landlordism and poverty of cultivators who are generally uneducated, absence of heavy machinery for cultivation and small holdings also create problem.
Two hundred and sixteen fungal strains were isolated from two hundred fifty soil samples collected from different localities of Punjab and subjected to screening for their pectinolytic ability using submerged fermentation. One hundred and fifty one pectinolytic strains were subjected to secondary screening and isolate IIB-13 gave the maximum pectinase yield (10.78±0.45U/ml/min) and identified as Aspergillus niger using morphological characteristics. Random mutagenesis (physical and chemical) was used to improve the pectinolytic activity of strain IIB-13. Nitrous acid mutant H-97 resulted in three fold increase (32.16 + 0.05U/ml/min) in pectinase production. This H-97strain was further subjected to optimization of media, carbon and nitrogen sources, temperature and pH. Maximum pectinase (37.01±0.11 U/ml/min) was produced using medium containing K2HPO4 (4.0 g), yeast extract (0.6 g), KH2PO4 (1.28 g), (NH4)2SO4 (2.0 g), MgSO4 (1.1 g) and pectin (10 g) per 1.0 L of distilled water at pH and temperature (7.0 and 30°C) respectively after 60 hours of fermentation. Fermenter studies (7.5 L) resulted in increased pectinase activity (40.31±0.07 U/ml/min) with decreased incubation time of 48 h using 1% inoculums with optimized reaction conditions i.e. temperature (30°C), pH (07), agitation (200 rpm) and aeration (1vvm). Fermentation kinetics was applied to validate the results. The crude enzyme was subjected to purification by applying ammonium sulfate precipitation and Ion exchange chromatography which resulted in 44.20 % yield with increased activity i.e. 75.18±0.04 U/mg. Km value of 2.30 mg/ml using pectin as substrate showed its maximum specificity for the enzyme. Activation energy (Ea) i.e. -28.95 KJ/mol and enthalpy of activation (ΔH) i.e. -26.73 KJ/mol were calculated employing thermodynamic studies. Characterization of enzyme revealed catalytic activity optimum temperature and pH as 25°C and pH 7. The enzymes catalytic activity was observed to be reduced by some heavy metals such as Hg2+, Pb2+, Cu+ and Cd2+.