Browsing by Author "Hasan, Md. Mahmud"

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Isolation and characterization of parasporal anticancer protein from Bacillus thuringiensis strains
(©University of Dhaka, 2025-02-09) Hasan, Md. Mahmud
Extensive research is ongoing to unravel the mystery of the diversified role of Cry proteins from Bacillus thuringiensis (Bt). Anticancer Cry proteins are named parasporins and have the selectivity to kill tissue-specific cancer cells without harming normal cells. These characteristics of parasporins have opened a new horizon of its anticancer activities. This study sought for investigation into new parasporal anticancer proteins from 98 nonhemolytic and 23 non-insecticidal hemolytic Bt strains from 298 indigenous Bt stock. Six sets of primers were designed from the conserved δ-endotoxin, CryBP1, and Etx-Mtx regions of ps1- ps5 and were explored to detect the presence of respective genes through PCR amplification. A total of 27 PCR amplicons were obtained from 121 Bt strains. Primers targeting the ps1 and ps3 (CryBP1) genes amplified desired fragments from the plasmid of 8 Bt strains. Besides, ps1, ps3 and ps4 primers amplified 19 unintended amplicons of various sizes. 25 PCR amplicons were sequenced from both anticipated and unintended amplifications. These generated no expected parasporin or cry genes from the DNA sequencing data, instead 11 plasmid-mediated genes were found, mostly of drug/metabolite transporters, Tn3 transposases, and DNA/RNA manipulators. Alternatively, extraction and purification of parasporal proteins followed by SDS-PAGE were performed from 98 nonhemolytic Bt strains. Of them, seven strains; MyIa2, FHSc4, KkSc1, RaSd1, MyIb1, MyIa1, and SgSp2 revealed some prominent parasporal protein bands with varied molecular masses (17-78 kDa). Among them, proteinase K-digested putative parasporal proteins from 3 strains, MyIa2, FHSc4, and KkSc1, were revealed as cytotoxic to the HeLa cell line. Phase-contrast microscopy also supported the presence of parasporal inclusion bodies from the same three strains. Interestingly, as proteinase K digested parasporal protein did not produce any visible protein band in the SDS gel suggesting that they belong to non-Cry or novel/ undiscovered categories of parasporal proteins which deserve more critical studies. Consequently, the research was covered to investigating the anticancer Cry protein in 23 hemolytic non-insecticidal Bt strains of which five strains produced putative parasporal protein bands on the SDS-PAGE. Bt strains Soil-46 and 28S were found to produce four putative parasporal proteins of identical molecular mass (101, 86, 76, and 28 kDa), whereas BD59S had three (101, 86, and 76 kDa). Besides, a 103 kDa protein band was found from Dsh4 and 45L strains. Approximately 64, 51, 45, 41, and 32 kDa fragments were generated from the putative parasporal protein extracted from 28S and Soil-46 upon tryptic digestion. BD59S had 64, 51, and 41 kDa protein fragments, while Dsh4 and 45L had 45 kDa fragments upon trypsin digestion. On the other hand, parasporal proteins from all five strains formed a 46 kDa identical protein fragment when digested by proteinase K. Then, untreated, trypsin-treated, and proteinase K-treated protein samples from each strain were tested for cytotoxicity on HeLa cancer cell lines. Untreated protein samples from 28S, Soil-46, 45L, and Dsh4 exhibited modest cytotoxicity on the HeLa cell line, while BD59S did not. The trypsin-digested proteins of BD59S exhibited significant cytotoxicity, whereas 28S, Soil-46, 45L, and Dsh4 showed moderate towards the HeLa cell lines. Proteinase K digested proteins of all five strains showed potent iii cytotoxicity on the HeLa cell line. In contrast, the same protein samples at the same concentration didn’t show any cytotoxicity to the normal cell, Vero cell line. In addition, the solubilized parasporal proteins of these Bt strains showed cytotoxicity to brine shrimp nauplii with an LC50 value of 114.19 μg/mL. Furthermore, they were nonhemolytic to sheep red blood cells and non-insecticidal to the fruit fly larvae (Bactrocera cucurbitae). All of these findings meet the requirements of being parasporins. Besides, as the untreated parasporal protein from 4 strains Soil-46, 28S, 45L, and DSh4 showed little toxicity towards the HeLa cell line hence this attitude of parasporal proteins someway coordinated with S-layer protein. Light microscopy showed the presence of round/ atypical parasporal inclusions, while SEM showed that all inclusions were round in five strains. Morphology analysis from SEM indicates that the parasporal inclusions are consistent with the S-layer protein. Whole genome sequencing (WGS) of four strains (BD59S, 28S, Soil-46, and 45L), three strains (BD59S, Soil-46, and 28S) were found belonging to Bt serovar finitimus, whereas 45L belonging to the serovar konkukian. Besides, bacterial WGS data analysis, the 101, 86 and 76 kDa SDS-PAGE observed protein bands were identified as 91 kDa, 86 kDa S-layer, and a three domain Cry-like 73.54 kDa protein, respectively. The 103 kDa protein band of 45L was identified as 103 or 93 kDa S-layer protein of these strains. As anticancer activity was identified in proteinase K and trypsin digested parasporal protein, hence they were compared with anticancer parasporin. The 91 kDa EA1, 86 kDa Sap, and 73.54 kDa Cry-like protein had 19% and 18% identity with PS3, respectively. Besides, the 93 kDa SLP had 16% with PS3, and the 103 kDa SLP had 19.84% and 14.22% similarities with PS3 and PS5, respectively. Based on the results, parasporal anticancer proteins of five indigenous Bt strains namely Bacillus thuringiensis BD59S, Soil-46, 28S, 45L, and Dsh4 are suggested to be as parasporin-like S-layer proteins. This is the first report of S-layer proteins from B. thuringiensis having anticancer potential in the HeLa cancer cell line while non-cytotoxic to the Vero cell line. The cancer-cell killing nature of parasporal S-layer protein from Bt strains thus opens up further investigations to unveil their anticancer potentials to become a candidate for anticancer protein development.
ISP Setup and Configuration with Mikro-thik and Linux Platform
(Daffodil International University, 2018-12) Hasan, Md. Mahmud
MikroTik operating system is designed for a network router. These functions include IP Addressing, Firewall & Nat, Routing, Bandwidth Limiter, Point to Point Tunneling Protocol, DNS server, DHCP server, Hotspot, and many other features. It is very useful for our daily life. In this sector we will know about Cisco, MikroTik, Cabling, Linux System etc. Network devices are connected to computers, peripherals, even LOT devices. Switches, routers and wireless access points are the essential networking basic. Through them device connected to network can communicate with one computer to another computer and with other networks, like the internet. Now today a large number of people all over the world usage internet technology with their dally life. So, the networking is so much important fact right now. Now-a-days every single people, business and e-commerce, every work station is fully depending on software-based communication and internet technology. That is the reason it’s extremely valuable to anchor the system. Computer system and peripheral are connected to form a network. They provide various advantages, for Example-Instant messaging, parallel computing, video conference, interaction with other users using dynamic web pages, sharing information by using internet or web.
Performance Analysis of Direct Sequence CDMA Power Line Communication Systems over the Frequency Selective Channel
(Department of Electrical and Electronic Engineering (EEE), BUET, 2005-11-20) Hasan, Md. Mahmud; Rahman, Dr. Md. Saifur
Outdoor power line communications (PLC) systems represent an additional and alternative for classical and communications. In this dissertation an analytical model of Direct Sequence CDMA power line communications systems has been developed for frequency-selective fading channel based on .the concepts of wireless communication. Binary phase shift keying (BPSK) modulation scheme is considered. The fading in power line is considered to follow Rayleigh distribution. During the analysis it is considered that power line channel can carry frequencies from I to 21.48 MHz (bandwidth occupation 20.48 MHz) and the chip rate would be 10.24 Mchips/s for DS-CDMA. The current research of power line channel modeling has been concentrated on home automation, broadband indoor communications and broadband data transfer in a low voltage distribution network between home and transformer station. A frequency selective multipath channel is modeled whose path gain is found to be Rayleigh distributed. A noise term has been introduced in the developed model, which consists of all type of noises in power line. To estimate impulse noises the statistical probability density functions have been used. On the basis of the analytical model, the performance of the DS-CDMA technique has been evaluated. The impact of power line noise and multipath propagation on signal to interference ratio (SIR) and bit error rate (BER) are then analyzed under various conditions. The performance parameters are evaluated as a function of number of simultaneous users.PLC with DS-CDMA is found to be a promising option for future telecommunication in a LAN and MAN.
Study on Chemical and Organoleptic Properties of Valueadded Potato Chips
(Daffodil International University, 2022-02-20) Hasan, Md. Mahmud
This study was aim “Chemical and Organoleptic Properties of Value-Added Potato Chips.” The ingredients for the final product were gathered from local and online markets, cleaned, chopped into bits, sun dried, and ground then mash the potato, add flour, salt. Make doe perfectly and boils as a roll and cut them into perfect shape. After sun dry frying into boiled vegetable oil. After that add the seasoning which is made with carrot and spinach granular powder, red chili, testing salt, salt, hot spices. Each stage is completed in a safe and sanitary manner. The temperature of the drying process is kept low enough so that the nutritious content of the food is preserved. In this study, it was discovered that s2 (with seasoning) had a higher protein content (16.29%) than s1(without seasoning) (15.167%). Also, s2 (with seasoning) has higher ash content (1.6%) than s1 (without seasoning) that is 1.16%. No microbial growth was seen in both s1 (without seasoning) and s2 (with seasoning). s1 (without seasoning) and s2 (with seasoning) were the two samples. The s1 has no vitamin A content but s2 contain Vitamin A (1372.25µg per 100 gm.). The sensory evaluation of s1 vs. s2 potato chips was performed by 80 panelists of various sensory parameters such as appearance, flavor, taste, texture, and overall acceptability. s2 (with seasoning) performed well in the quality parameter test, and the panelists agreed that it was the best in all sensory attributes. The study also revealed that among the panelists, s2 (with seasoning) was more acceptable than s1 (without seasoning).